Where Two Deserts Meet

In this episode of Where Two Deserts Meet, we meet up with National Weather Service Meteorologist, Jessica Leffel, and explore the complexities of the monsoon season and what visitors should expect during this time of year when visiting Joshua Tree National Park. We also catch up with Alex Snay, Joshua Tree National Park’s Facility Manager to learn about the importance of safety during flash floods and why we say, “Turn Around, Don’t Drown.”

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TRANSCRIPT:

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Donovan: Where two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Chauilla, Mojave, and Chemehuevi people as the original stewards of the land in which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place, and we pay our respects to the people past, present, and emerging who have been here since time in Memorial. Ian: Hi, I'm Ian. Donovan: And I'm Donovan. Ian: And we are both park rangers here at Joshua Tree National Park, Where Two Deserts Meet is an official podcast of Joshua Tree National Park, where we explore topics that often require a bit more detail and the help of an expert in the field to gain perspective. Donovan: Hey, Ian, did I ever tell you about that one time I almost got caught in a flash flood? Ian: Uh, no. What happened? Donovan: During the summer of 2022, I was stationed down at Cottonwood Visitor Center for the day, and the drive down was pretty peaceful and covered with blue skies. As the day went on, I remember often looking outside the west facing window and I started to see denser and denser clouds form. I remember actually being pretty excited by this image because usually that means that the sun will be blocked by them. Providing a brief moment of shade, which can feel amazing, especially when it's usually over a hundred degrees Fahrenheit outside. That feeling of relief was short-lived. However, as those white fluffy clouds soon turned to a dark gray cover, blocking all sunlight completely, what once was a pleasant Sunday afternoon? Looked as though it was now. 8:00 PM at night. It was clear to me that the rain was coming and I needed to get back as soon as possible. Luckily, we had just closed up the visitor center and we were getting ready to drive back up to headquarters. As we started to drive, we heard sounds of thunder in the distance. We could see some signs of rain about five to six miles east of smoke tree wash just off of Pinto Basin Road there. But luckily, no signs on the road. We were actively driving as we turned the corner. Suddenly we started to see a small stream form across the porcupine wash area. The water was only about one to two inches deep, so I decided to push forward. I then pulled over and waited just to keep an eye on the situation, but not even after one minute of driving through what was a small creek, it had now become a river at least. Four to five inches deep. I got out of the car and put on a safety vest to stop incoming cars from passing through the flood. After about five minutes, the water was almost a foot deep and I could see large rocks in boulders being pushed onto the road by the force of the water. I radioed the rest of the park to let them know that there was a flash flood occurring. The amazing part about all of this that I'm still surprised today about flash flooding is for myself and those cars that had to wait that day, we only waited about 20 minutes for that water to come and go. As fast as it came, it went and everybody was able to proceed on with a regular day, you know? Ian: I feel like that's actually sort of a common story. Most rangers at Joshua Tree National Park have had their own flash flood story after living here for a while. Your story reminds me of how hard it is sometimes as a ranger giving informed advice to visitors, considering sometimes we get those visitors who really want a definitive answer on if rain will impact their trip or not. Sometimes the only thing we can advise them is to be prepared for anything, especially during the monsoon season when it's hot and summery and rain is the last thing most visitors expect. But the monsoon season here has played a significant role in shaping the desert. Donovan: I feel like the weather here in the desert often confuses a lot of people. The extremes of day and night temperatures elevated precipitation in the summer. I think it's about time we consult a meteorologist on this one. Ian: Wait. What do meteors have to do with weather? Dononvan: Oh, okay. Ian, you know what meteorology is. Ian: I know. I just couldn't let us get away with doing a meteorology episode without making the joke once. But really though meteorology is no joke despite its misleading name. Meteorology goes beyond just the study of weather. The atmosphere and its phenomena. Donovan: And of course when talking about meteorology and Joshua Tree National Park, it would be impossible to do so without mentioning our friends at the National Weather Service in Phoenix, Arizona, who we rely on daily to have the most up-to-date weather inside the park. Luckily, a meteorologist at the National Weather Service agreed to talk with us on all things weather and especially the complexities of the monsoon season here in Joshua Tree National Park. Jessica: My name is Jessica Leffel and I'm a meteorologist at Nashville Weather Service Phoenix. Uh, we have over 120 different weather forecast offices across the country, and they stretch anywhere from Puerto Rico to Guam, but here in Phoenix, we actually cover South Central Arizona, stretching all the way into Southeast California. And we do a variety of different things here. So we'll do anything from forecasting to aviation weather to DSS, which is decision support services, helping our political partners out if they have events going on, as well as looking out and doing outreach events too, and doing the best that we can to get out into the public and educate people on weather preparedness. Donovan: On top of all that, Jessica is a part of the team that plays the important role of providing the weather forecast for Joshua Tree National Park. We utilize their weather resources in all our daily operations, visitor education and resource management. In the desert where weather conditions are often extreme, receiving alerts of potential hazardous conditions is often critical to visitor and park staff safety. But before we dive into that, we ask Jessica, what does an average workday look like for a meteorologist? Jessica: Depending on the day, you know, usually right now we're starting to get into the monsoon, so, our shifts will be a little bit more occupied. But outside of that, we do have routine shift duties that we have to get accomplished. So that's putting out our forecast. So that's something that anyone could go on our website to see what the high and low temperature's going to be, what the winds are going to be like, or all of those different. Variables that they're interested to know about the weather. We also put out a forecast discussion as well, and that kind of covers goes over our understanding of what's happening in the upper air and giving a better idea of synoptically what's happening so we can explain our reasoning and what different things we're seeing to cause the current weather that we're having. On top of that as well, we'll also put out an aviation forecast and that will include things called T A Fs. TAFs for short, and it's a terminal arid drum forecast. So this is something that we provide for the different airports within our region. So we have, currently about five airports that we create these forecasts for. And they'll go over any conditions or any changes so that the airports are ready to go and know if they need to change their runway configuration, if there's gonna be a wind shift, for example. Um, just to increase the safeness of the taking off and landing of airplanes. Beyond that as well, we do answer lots of public phone calls anytime anyone has any question about what's going on with the weather, as well as answering phone calls from our media partners to produce interviews to give, the public a better idea of what's happening and what different things that they can be prepared about for upcoming weather. And then beyond that, whenever we get into the actual activeness of the monsoon and the height of everything, we'll start putting out watches and warnings and advisories and doing the best that we can to warm the public before severe weather is approaching Ian: Meteorologist do a lot more work behind the scenes to keep us safe than we can even imagine. However, we often take weather forecasts for granted as they are often much more work to produce than it takes to access them. It's easy for us as the general public to open up an app on our phone and within seconds get an idea of what the next seven days of weather will look like almost anywhere in the world for a meteorologist. It's much more than that. So what exactly is happening behind the scenes of those forecasts? Jessica: With weather prediction, we do a lot to look at the current state of the atmosphere, and then we also look at a bunch of different models and different things to see how the atmosphere is going to evolve and then change our forecast. So we'll look at lots of current observations. So we'll check out what's happening with surface observations, what's happening with satellite imagery, what's happening with radar data radio, saw data, upper air data, and much more to get a big picture idea of what's currently happening. And then we use our pattern recognition and the skills that we learned in school from our foundation of understanding the upper air and the atmosphere and the different changes that it goes through, depending on the atmospheric pattern, we're able to see how this situation currently is going to evolve, and then that helps us predict whether and then make our forecast. Donovan: So there's surface observation, satellite observations, radar data, and more. There are so many complex resources and factors that go into the forecast that we receive. This reminds me of a common visitor question I get, which is, I'm camping in Joshua Tree National Park about two to three months from now, what will the weather be and what can I expect? And honestly, us rangers can give you an estimate based on past weather averages in the park, but to provide specific details that far in advance is quite complicated. Jessica: We produce a seven day forecast. Obviously, the closer it is in time, the more accurate that it will be. Just because we're able to get a better idea of what's happening currently and from day to day, we're able to see that variation in those small minute details and understand what's gonna happen a little bit better. However, as we get further on the forecast, things can definitely change. That isn't to say that long lead forecasts are not accurate. We do have, you know, a climate prediction center that will put out three month outlooks and things of that nature that can be fairly accurate. But as we get closer, we're able to see what those local influences will be a bit better. So for example, with this current monsoon and the climate prediction center was forecasting above normal temperatures and below normal precipitation for much of our region and our office. So with that, we were able to get a better idea of what we were going into, but as it's gotten closer, we were able to see how things have evolved, how it's changed, and create a more. Specific forecast that's more detailed with the current observations that we have now to better formulate our, our forecast. But closer it is the more accurate it is. But the reason that we do seven days out is because those are our, our highest confidence intervals. If we started doing eight days and beyond, then we would have more uncertainty in the forecast and there would be more changes. So we feel very confident with our seven day forecast. So that's why we release those to the public. Ian: Some confidence is very important when predicting precipitation in the desert, and we know precipitation isn't always the first thing that comes to mind in the desert, but why is that? What causes some landscapes to get large amounts and others to get maybe just a few inches a year? Jessica: A desert basically just lacks the available moisture to pull from in order to produce precipitation. So that could be due to a variety of different factors, whether that's the atmospheric circulation pattern, and you're over a high pressure system, which is usually in tuned with hot and dry conditions, or if it's the prevailing wind pattern that is. Producing an effect or topographic barriers and terrain influences or different temperature variations. So there's many different factors that can cause a desert to not receive as much rainfall as exterior regions that might receive more. So Joshua Tree National Park is under the influence of what's called the rain shadow effect, and this is essentially just the absence of rain on the leeward side of the mountain. So with that as air cools, as well as climbs over a mountain range, it begins to dry. So because we've got Mount San Jacinto as well as Mount San Gorgonio, just west of Joshua Tree National Park, as this air moves in, it is then pushed up by these mountains, and then it cools and dries as it rises over the mountains. So then, Only the mountains are really receiving that precipitation. And by the time that it reaches over the mountains and gets to the leeward side of the mountain, it doesn't have any moisture left to pull from. So the water vapor content is significantly decreased, and then we can't get as much rain in Joshua retrieve because of those mountains just west. Donovan: So when visiting Joshua Tree National Park and traveling from places like Coastal California, you may get a glimpse of two large and often snow capped mountains just west of the park. The leftover rain from those storms that hits those mountains often isn't much. For example, big Bear Lake located at the top of San Gregorio gets about 70 to 80 inches of combined snow and rain every year. Whereas Joshua Tree National Park only gets about four to seven combined inches annually. This is a huge difference when you consider that these landscapes are only a handful of miles apart. This doesn't mean that the rain can't catch people off guard here, though. Ian: Yeah. No matter how much precipitation a place gets annually, it's always important to plan ahead and check the weather. But interpreting the forecast is also important. Like the whole probability of precipitation can be a little confusing. Like what exactly does 20% chance of rain mean? Luckily we have Jessica. To clear things up. Jessica: Yeah. So whenever we're giving probabilities and different percentages of what's happening with rain coverage, um, just know that that is for aerial coverage. So if it says 20% chance for Joshua Tree National Park, it's for the region. It's not necessarily saying that there's only a 20% chance of rainfall in one specific location. So you have to kind of take it with a grain of salt and understand where that probability is coming from in order to better have a better idea if you're gonna need to bring an umbrella or not, for example. Donovan: Being prepared for a potential thunderstorm can make a huge difference in the success of your trip. Summer is the most common time of year. People don't expect rain in the park, but those who live locally often, once summer comes along, it's on everybody's mind. The monsoon season is why Joshua Tree National Park often gets a majority of its rain during the summer months, but what exactly is the monsoon season and what can visitors expect from the weather during this time of year? Jessica: What will happen during the monsoon is our high-pressure systems will relocate themselves to create a more favorable pattern for thunderstorm development. So what happens there is by late spring, heading into early summer, we start to see strong solar heating take place, which causes hotter temperatures, and then our surface air pressure starts to decline. And then this formulates what's called a thermal low. From there on the difference in surface air pressure starts to cause the air over the ocean, which is more moist in nature and cool to be pushed into these hotter and dry regions. And as that air pushes in, it also brings instability with it, causing these sun to develop and the three main ingredients that you need for thunderstorm development, our moisture, instability, and uplift. So as that moisture comes in, we're able to get those thunderstorms develop. And because there's currently thunderstorms happening, It increases the humidity in that region, so more thunderstorms are able to take place. Um, and then from there we also have the unstable air. And then we're seeing, uh, as I was mentioning, those uplift is another ingredient that we need. So that's why we usually see our monsoon thunderstorms will actually start over our higher terrain features first. So any mountain ranges. Will get that precipitation to start there first, and those storms will start there and only if they're strong enough will they make their way to lower elevations. And it's just because the uplift mechanisms that are reintroduced with those higher terrain features allows air to push upward, and then the instability works along with the moisture to create those storms. So usually as we start to move into those lower elevations, we're losing out on that uplift mechanism that helps create those thunderstorms. And it's why it's only those stronger thunderstorms that are actually able to make it to lower desert areas. But beyond that, once this occurs and rain falls, you know, we're able to have this loop where we have continual moisture and that. Whole season is able to continue and continue having thunderstorms because that available moisture is there to pull from and then it doesn't actually decrease and fizzle out until surface temperatures start to decline. And then from there, there's not so much of a difference between our surface air pressure and there's no longer this competing force there. Ian: As Jessica mentioned, those monsoonal storms often form around high geographical features for Joshua Tree National Park. The two most prominent peaks to find a storm forming around are Queen Mountain, just north of Skull Rock and Pinto Mountain, just east of the Choa Cactus Garden. Once that moisture cycle starts, those storms can rapidly form over the next few days, all throughout the park. Donovan: We often get visitors who are from other areas where monsoon storms don't regularly occur and often mistaken them for something like a tropical storm or cyclone, thinking that they are similar, but although similar in appearance, they aren't the same thing. Jessica: Yeah, so a monsoon is a season, as you mentioned, so it is a calendar based definition of June 15th through September 30th. Um, that doesn't mean that monsoon thunderstorms can only occur during this timeframe. It's just when we commonly see them and when we have usually the pattern developed for those favorable thunderstorm conditions in the upper air. However, you can definitely get those thunderstorm patterns outside of that as well. So a monsoon is a. Season, it's something that will occur over an extended period of time and over a larger region as well. So, for example, we are under the influence of the North American monsoon. So this is a, you know, continental pattern that happens, whereas a tropical cyclone is a more individual in nature storm. So you can have multiple tropical cyclones happening at once or just an individual one. But with that it's individual in nature. It's moved by specific high and low pressure systems competing, and it's more of a frontal boundary or things that are happening there that are causing it, rather than the overall pattern allowing for this favorable condition to happen for months on end. So a tropical storm instead is, Just a strong rotating calm of air, usually centered by a low pressure, and it's, got a closed, low level circulation that's able to produce those very strong winds and heavy rains and squall lines and things of that nature rather than the monsoon itself, which is a full on season and has these conditions for an extended period of time. Ian: So to put it in a way that hopefully makes it easier to remember, the monsoon is an entire season of atmospheric changes. Unlike tropical cyclones which operate individually, one thing they do have in common, Is rain and lots of it. A monsoonal storm can cause a rapid downpour of precipitation to concentrated areas causing something called flash flooding. But why do flash floods more commonly occur in the desert compared to other regions? Jessica: So we get more flash floods during the monsoon because we have longer duration precipitation events. And with that as well, our region and our soil content isn't able to necessarily take in moisture as well as other regions might be. Also, it has to do with our infrastructure and the way that roads are built in and the way that things are built over the years and how we have different regions where we have lower elevations and these low water crossings that as rain falls and pools, it obviously has its runoff pattern and finds the lowest spot possible to continue its path and it. Finds those lower spots and, and reaches into them and fills those regions very quickly. So anywhere where we have maybe a road that maybe should have been a bridge or um, has a dip in the road there, um, is more susceptible for water to pool there. So it's just those low water crossings, those lower lying areas where water will then accumulate very quickly. Um, and then from there, flash floods are just more common during them monsoon because we get heavier rainfall at that time and for more longer durations as well. Donovan: As Jessica mentioned, rain will often find the path of least resistance, allowing it to collect in runoff areas, which often compose a huge risk to our safety. Jessica: Yeah, so flash loads are extremely dangerous. It only takes six inches of moving water to knock over an adult and then 12 inches for, um, small cars to be moved away as well. And then we get up to 18 to 24 inches, can actually push away a large SUV or trucks. So it's really not that much moving water that can get things to start pushing and moving. Um, and with that as well, flash flooding is, Very dangerous and, and causes a lot of different drowning events, so people might not think, oh, this low water crossing here, I'm seeing some flooding happening and think, well, I'm in my truck. I'll be fine. I can go ahead and drive through this. That's the most dangerous thing that you can do in that case. So if you come across a area where there is flooding, never drive through the water, you definitely wanna turn around because people often underestimate the power of water and power of moving water and how strong it could be. So you might face a situation where you're now stuck and you can't swim your way out because the current is just. Too strong and your vehicle is now not even attached to the ground anymore. It's now hydroplaning completely, and you just have no way to get out besides getting rescued. So it can be very dangerous and it can get very dangerous quickly, um, as flood waters escalate very fast. Donovan: According to the National Weather Services website in 2022, there were 102 fatalities caused by flooding and 146 in 2021. As Jessica mentioned, it does not take a lot of water to sweep you off your feet. Six inches to knock over an adult. 12 inches to move a small car and only 18 to 20 inches can move a large truck. When these floods occur, they're not only rapid in their appearance, but fast moving with great force. Ian: Unfortunately, flash floods are not the only safety risk when it comes to monso storms. There's also lightning, that loud flash of light coming from a storm cloud, often causing destruction to whatever it encounters. What lightning is, in simple terms, is an electrical discharge caused by the splitting of atoms, often moving across the sky in the path of least resistance. As its energy is released, it can be extremely dangerous to be caught in its path, although you have less of a chance of being struck by lightning compared to being caught in a flash flood. It's still important to be prepared and know what to do in case of a lightning strike. Jessica: So lightning is very commonly associated with storms. With that. We can even receive dry lightning when we might have a storm that doesn't have much precipitation with that, and lightning is incredibly dangerous. People often underestimate the power of lightning and think, I'll never get struck by lightning. That's incredibly rare. While it is rare, the cases have risen each year in the United States, so it's important that we're prepared and know what safety procedures we can follow whenever we see a storm coming, in case that is accompanied by lightning. One of our favorite sayings to say around here is when thunder roars go indoors. So anytime you hear thunder, go ahead and go do what you can to get inside. If you're already in the park, go ahead and hop into your car. It's also safe to be in a metal hard topped vehicle because if lightning were to hit your car, it would actually go around the exterior of your vehicle rather than ate you as you're inside. Also wanna say, make sure you're seeking shelter, not in something. That would be an open building or open feature. So if you're under something that looks similar to a bus stop, for example, where it's open and doesn't have closed features that would not be considered safe. So do what you can to get into a closed vehicle . If you can get into a building, that'd be great. If there's a visitor center nearby, run in there. That would be the most safe location. And also wait until 30 minutes after you last your thunder to go back outside and resume your outdoor activities. Donovan: When thunder roars go indoors, it's as simple as that. Luckily, our friends at the National Weather Service have systems in place to make sure that we are aware and prepared for such events. When looking at the weather forecast, you may see terms like watches, warnings, and advisories, but what exactly do those mean and what should we do if we see those alerts? Jessica: We will very closely monitor storms and any different factor that we put out, watches, warnings, and advisories for. Um, what we do have is certain criteria in order for things to become a watch versus a warning versus an advisory. So if something is more severe in nature, then it would be considered a warning. Um, and just to break down the definition of each of them, a watch is something where we notice that there's. Favorable conditions for something to develop. Whereas a warning means that conditions are currently happening or very imminent and it's severe in nature, it's gonna cause a lot of different impacts and, um, be more hazardous. Whereas an advisory is very similar to a warning in the sense that it's. Imminent or currently happening, however, it's sub severe. Usually the conditions aren't gonna be quite as impactful or cause as many hazards as a warning would cause. Um, so in that case, anytime we're going through and we're monitoring a storm system or whatever it might be, we're seeing if it's able to meet a certain criteria to be elevated or upgraded to the next step. So whenever we have a watch out, that means that we've noticed that there's favorable conditions. We're keeping a close eye on it, and then only when we see that those conditions actually meet our criteria and break a certain threshold, will we upgrade that then to a warning? Donovan: Jessica had a great analogy of a s'more when talking about weather alerts. Imagine you have all the ingredients of a s'more. You have the chocolate bar, the marshmallows, and some graham crackers, but they aren't quite put together yet. That is sort of like a watch, just like the s'more. All the ingredients of the atmospheric phenomenon are there, but it hasn't quite happened yet. So now let's say you put all the ingredients together, you've got a fully structured s'more. That would be an advisory. The phenomenon is here and it's actively happening, but now let's imagine that maybe the person who made you this smore, double stuffed it, little extra chocolate running down the side, marshmallows, getting all over your fingers. It's just overall a little bit more intimidating. That would be a warning, just like the advisory, the atmospheric phenomenon is here, but it's much more intense. Jessica: So a watch we would recommend just be prepared. Know that this could happen. So with a watch, you wanna be prepared and be ready to go in case you need to take action. Whereas a warning, you need to take action immediately. So if we're saying that there's gonna be a severe hail threat, then in that case, take cover immediately. Get what you do, what you can to get into the safest location as possible, and just make sure that you're taking it seriously because a warning is not something that we play around with, especially because that does activate. People's phone systems. So we, we don't wanna put out a warning unless we're confident about it. So when you see a warning, definitely take caution and, and do what you can to, to follow safety procedures in that case. Ian: Hopefully you're feeling pretty prepared to make a safety plan for yourself in case of an extreme weather phenomena. Before we wrapped up with Jessica, though, we got a chance to ask her what meteorology meant to her and why it is important. Jessica: So meteorology just boils down to the study of weather, but it really goes much far beyond that. As far as being a meteorologist. So yes, we have the foundation that we need from schooling and from taking all of our necessary prerequisite classes to develop this understanding of the science behind weather. Um, but what's really important as meteorologists, that we have the ability to communicate this to the public because ultimately, if we create these forecasts and come up with all of these solutions and have all these groundbreaking scientific discoveries, but we're not able to reach the public and then communicate that information, it's all for nothing. So it's crucial that meteorologists really take the time to really get into the public and, and tell them what's happening. Um, because really we're the barrier between these natural disasters happening and the public being informed and ready to know and know when they need to evacuate. So it's a really important job because it can ultimately save lives at the end of the day. So it's, it's much more than just studying the weather for the fun of it. We do it so that we can have better lead time for whenever we're expecting severe weather or things that will eventually cause hazards and impact the public. We just do our best to not only just study the weather and do our best to contribute what we can to the research and meteorology as scientific field, but also what we could do to educate the public and make them be more weather prepared. Donovan: So now, Whenever you check the forecast to plan an event, take a trip, or even go on a hike, you can thank meteorologists like Jessica for helping keep you safe by providing that information. Ian: Of course, visitor safety here at Joshua Tree National Park doesn't stop there. We have teams of rangers dedicated to ensuring you stay up to date on park conditions and closures due to hazardous weather all throughout the park. Someone who knows a thing or two about flash floods here at Joshua Tree National Park is Alex Nay. Alex: My name's Alex Nay, and I am the facility manager here at Joshua Tree. Previously, I was a road supervisor from 2017 until last month. Donovan: During the monsoon season. When flash floods occur, park visitors should seek shelter by driving out of the park. However, Alex and his team are usually the. First ones on scene to check road conditions and safety, but he does much more than that here at Joshua Tree National Park. Alex: So as a road supervisor, when we come in, in the mornings, we'll go over all the projects that we're working on for the week. We'll go out depending on the time of year, that usually dictates what kind of projects we're doing here in the summer months we're usually in vehicles staying out of the heat. We also take care of all of the road signs that you see, all of the gates that you see as you drive through the park. We also make sure that the shoulders and the drains in the shoulders are prepared so that when we do get rain here in the monsoon season, it's able to flow off the road. Ian: Alex has helped the park manage a lot of flash floods, which can vary in degree quite a bit. We asked Alex if he could give some perspective of what he tends to expect during the monsoon season. Alex: I started working here in 2016. I would say I've been through at least 50 monsoonal rains here in the park. Most years we get about five to 10 heavy rains that we actually have to go out and do mechanical removal of sand off the road. I would say every year it'll be a few days where we get light rains and then we'll get one heavy day of rain. Last year was an anomaly as we went in about 40 days getting rain every day somewhere in the park. Donovan: Alex is referring to the summer of 2022, where a majority of the summer consisted of cloud coverage and record breaking thunderstorms. That monsoon season didn't just affect Joshua Tree National Park, but our other neighboring park service units as well, such as Mojave National Preserve and Death Valley National Park, referring back to a press release from Death Valley National Park on August 5th, 2022. Unprecedented amount of rainfall. Caused substantial flooding within Death Valley National Park. All roads into and out of the park are currently closed. There are approximately 500 visitors and 500 staff members unable to exit the park. This catastrophic event was caused from a sudden downpour of 1.46 inches of rain onto the 1.47 inches from the previous day. That might not seem like a lot, but their annual rainfall is usually less than two inches. According to the release, no one was harmed, but effects of weather events like this are long lasting Here in Joshua Tree National Park, we do everything we can to prepare for extreme flash floods. Alex: So our monsoon season runs from the end of June to the middle of October here. Usually what happens is in June we'll start going through identifying any low areas in the road shoulder that we have to fill in. We'll start making sure that all of the drains that are on the side of the roads are opened. We do a lot of maintenance throughout the year with our shoulders. We'll keep 'em bermed up just so that people are not trying to drive down the drains. And then in the summer before monsoon season, we'll come out and we'll open these drains up to make sure that the water has a good path to get off the road. We also do a lot of work on our dirt roads to make sure that those have the same type of drainages through the windrows to make sure that any rain that comes onto those roads are able to get off. We have a lot of historic roads here in the park and some of these areas are really low and it's hard for the water to get out of them, so we try to create areas in which the, the water can help shed off the road so that, say a visitor is back on Bighorn Pass Road and they get rained on, they're able to get out of there before they're fully closed in by flooded roads. Another thing we'll do is we'll go and we'll pre-stage a bunch of signs around the park to let visitors know that there might be flooding ahead, or there might be areas where there's standing water. You know, standing water in vehicles is not a good mix, you know, hydroplaning happens. So we try to give visitors as much warning as we can when they come into the park that, hey, there's gonna be rain, there's gonna be danger ahead. Make sure that you're, you're paying attention as you drive through the park. Ian: So remember, if you see any sort of closure or warning sign, it is placed there for your safety. It is sometimes hard to conceptualize how water can tear apart a road, but it can happen. Alex: Here in the park, we have various areas that the monsoons affect differently. This is generally how roads are constructed. Here in the desert, we have shoulders that are soft shoulders, they're made up of loose sand. That sand gets compacted over time, but when fast running water that goes over these shoulders, it'll wash away. The water will continue to move on down the side of a hill. It'll take that sand with it, and eventually the asphalt will get undercut. Once that asphalt gets so undercut that it's no longer supported by anything underneath, then that's when the road collapses. This can happen where culverts are installed. If a culvert gets plugged up, this can happen in areas where water has a long runup before it actually gets to the road. There's very little to slow the water down. So once that water's getting to a road network, when it comes off the mountains, it adds a lot of velocity and it's taken a lot of the sand away, and eventually that sand, that's basically what's holding the road up here in the desert. When that is gone, then the road starts washing away. Ian: Once that road is undercut, it is no longer safe to drive on. A common visitor question I get, however, is I'm in the park and a flash flood occurs. Where should I go and what should I do? Although flash flooding could occur almost anywhere through Alex's experience, he's able to identify several areas that are more susceptible to flash flooding and how to stay safe while driving near them. Alex: Here in the park, we don't really worry about that too much in the northern part of the park. That stuff happens a lot down in Pinto Basin Road down to the Southern boundary. So if, if you're south of Cholla Garden on a dirt road, say Dale Road or Black Eagle Mine Road, and you see rain clouds coming, you want to exit the area and get back to Paved road, those areas, Have a very, very fast water flow. When that water comes off the roadway so much that we can lose a foot of road, a foot of sand off of that dirt road. Within minutes in the Cottonwood campground area down to the south boundary. The water basically runs through the canyon. It crosses over the road in various areas. That area, we get boulders two to three feet in size on the road. You don't want those hitting your vehicle. If you're in a park and you see heavy rain clouds coming, usually if you just stay where you're at, you'll be fine. Uh, one nice thing about Joshua Tree is we don't have a lot of area for, for water to gather. So when the rains come, we'll get quick flash flooding, and then within a half hour to 45 minutes, most of that water is receded to the point to where you can continue to drive either further north or out the southern boundary of the park would say. As you're driving through the park after Monsoonal rains, make sure that you're watching the sides of the road. That road still might be held in place just due to the nature of asphalt, but eventually that road will collapse and you don't wanna be on top of it when it happens. Donovan: Alex and his team will not only respond to flash floods, but will often do preparation beforehand. They will often pre-stage in more susceptible areas for flash flooding, and then from there they wait and watch. Alex: The flash flooding starts with a slow trickle. Imagine like you're filling up a bathtub right in the beginning. As soon as that water starts building up, it slowly starts creeping up in depth. That's kind of how a flash flood is. And then all of a sudden, the next thing you know, you've got boulders rolling through the road. You have water flowing over the road at a very fast pace, and once that water gets up to halfway up the side of your tire, that's when you, you gotta worry about floating away. But there's no connectivity in Joshua Tree. So we'll let visitors know that, hey, rains are here, or they're coming, you should exit the area or. Hold in place. Once we start seeing the water come across the road, we'll put in blocking positions. We'll make sure that visitors don't go through these areas. When we get heavy rains, uh, we usually get about 20 miles of roadway that can get covered in sand. Ian: Once that damage or coverage of debris occurs, Alex's team kicks into action to plow the debris off the road or determine if the road is even safe to drive on at all. If not, a closure might be needed. Closures only occur when absolutely necessary. So it is important to take them seriously for your own safety. Speaking of safety, Alex had one last piece of advice to give visitors when visiting the park during the monsoon season. Alex: I would say during monsoon season, pay attention to all the weather alerts. Also follow the park social media pages while I'm out and about. Take photos for record purposes, and I send those in into our social media people. So you might get an idea of what's going on in the park. Donovan: What we communicate with you, whether in the visitor center or on social media, it's always with your safety in mind. We understand that not everything can be planned for, but nothing can ruin a trip faster than not being prepared and having to face the unexpected head on. It's your trip and your experience. Ian: So remember, thank a meteorologist while checking the weather. Ideally, don't get struck by lightning. Pay attention to road signs and try to plan ahead for the unexpected. Donovan: Where Two Deserts Meet is an official production of Joshua Tree National Park, produced and edited by Donovan Smith, co-hosted and written by Donovan Smith. And Ian Chadwick. We'd like to extend special thanks to Jessica Leffel and Alex Snay for taking their time to talk with us. Sharon Lee Hart for letting us use her art titled Split as the Cover Art for Where Two Deserts Meet and Barstool for their songs, Lengthy, luckily fills Slowing Lover and Feathers Soft. For more information about the park and current conditions, visit our park website at www.nps.gov/jotr. Happy Trails.

In this episode of Where Two Deserts Meet we set out with Historical Landscape Architect Genna Mason-Bjornstad. With her guidance, we investigate how history can be traced across the landscape, the methods and efforts that go into protecting it, and how preserving these historic sites can help us learn from the past.

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Ian: Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land on which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place. We pay our respects to the people past, present, and emerging who have been here since time in.

Ian: Hello, I'm Ian.

Donovan: And I'm Donovan.

Ian: And we're both park rangers here at Joshua Tree National Park. Where Two Deserts Meet is a podcast where we investigate topics that often require a bit more detail and sometimes the help of an expert in the field to gain perspective. Through interviews and investigation, we bring you the unique details, research, and stories that make Joshua Tree National Park remark. Speaking of, what is remarkable is the number of cultural landscapes that reside within Joshua Tree National Park that most visitors don't know about. Now, I know the idea of a cultural landscape probably sounds pretty unfamiliar to most people. Imagine if you were told that even just driving through the park for an hour, you likely passed multiple cultural landscapes. You'd probably wonder if you missed that part of the park map.

Donovan: I mean, even just talking about it, I'm starting to think that I might have missed one or two here and there on the park map as well. Could I drop a finger randomly on the park map and it would be part of a cultural landscape? Is Hidden Valley a cultural landscape? Skull rock, even Oyster Bar. Okay. Well, sometimes it just feels like every time when I'm explained to what cultural landscapes are, there's always more to unpack.

Ian: All right. Let's not get ahead of ourselves. I totally understand. Cultural landscapes may be confusing at first, but they are certainly important to the National Park Service, and that's because the spaces where the works of nature and humans combine provide a sense of place and identity. They map our relationship with the land, yet the subtle details are not as easy to find as one may think. An important sign of Joshua Tree National Park's history is the historical structures and artifacts found tucked within the rocks and the different areas of the park provide diverse resources, often causing human life to gather in areas that provide essential needs, leaving behind vast amounts of historical evidence. This evidence on the landscape can take many forms. A common one within Joshua Tree National Park is homesteads and the large amounts of materials used in mining operations that may have been left hidden within the land where Joshua Tree National Park exists.

Donovan: Wait a second. Ian, you are telling me that if I go wandering through the park, I might come across some historical treasure. Last I check, the visitor centers don't have treasure maps.

Ian: All right. why well, yes, but no. Well, one of the amazing things about cultural landscapes is the collection of archeological evidence. They hold those artifacts and items. Are more than just historic trash. They also have significance by simply being within the context in which they are found. That context is an essential part of what a cultural landscape is. While there is no secret treasure or map, even a simple hike on a trail found on the park map can reveal hidden stories.

Donovan: And of course, if you do find something, you must leave it where you found it. In order to preserve that context. For example, visitors could potentially come across a surely useless rusty can in a seemingly random part of the park. But what a lot of people don't realize is that that can has been left there on purpose. That's because that can, being left where it was last used provides context as to who might have used that area before. It reminds me of one of those most common principles of leave no trace, which is take only pictures, leave only footprints. This not only applies to natural resources, but cultural and historical ones as well.

Ian: Totally. And with Joshua Tree National Park's vast history, there are quite a few cultural landscapes found within the park, but you know what? We should talk to Joshua Tree National Park's very own historical landscape architect, Genna, she's awesome and will have a lot to share on this subject.

Genna: I'm Genna Mason Bjornstad. I'm a historical landscape architect at the park here, and I'm the lead for the Historic Preservation program. A cultural landscape is a place that represents an important thing in history. It could be associated with a person. It could be associated with an event in history or could be representative of a design, a theme in Joshua Tree. We have quite a few cultural landscapes that are associated with the mining that took place in the park. There's the Lost Horse historic Mining District. There's the Northern Pinion Historic Mining District. There's the Pinion Mountain Mining District. There's also the Keys Ranch Historic District, which is associated with the mining, but it's more of a habitation site where there was a family living and home studying. Here we have five that are currently documented with a cultural landscape inventory. We have two more cultural landscape inventories in the works right now, and there are many other cultural landscapes within the park too that have not been fully documented, but have been recorded either as archeological sites or parts of them, but we'll get there.

Ian: All right, let's quickly break all that down. Defining a cultural landscape is all about looking at the interaction of historical or manmade resources and the chunks of natural landscapes they exist in and even possibly change with their presence. It takes a lot of work to determine where the cultural landscape ends and the natural and largely undisturbed landscape begins. This process of defining helps to identify things like developments, significance, natural register of historic places, and other valuable information. The landscapes can illustrate many things though, and they can even paint out broad patterns of American history that are more recent than people may imagine, like Mission 66 architecture.

Genna: Mission 66 historic districts that incorporate areas of development from the Mission 66 building program time when throughout the park service there was a lot of construction going on in development in national parks to celebrate the 50 year anniversary of the Organic act. And in Joshua Tree, we have the Cottonwood Mission 66 Historic District, which incorporates the Cottonwood Ranger Station and the housing area and the campground as well. And also our entrance monuments are from the Mission 66 era entrance monuments.

Ian: Do you mean the signs that everyone likes to take their picture in front of?

Genna: Yes. We are kind of inventorying everything that's associated with that historic period. or even the things that aren't associated with it, just so that we can understand what's in that landscape altogether. And you know, the cultural landscape inventory itself is kind of a framework for standardizing and identifying what is within that landscape we are looking for. The NPS has identified 13 different characteristics that are part of a cultural landscape that can kind of incorporate everything that is in there. It includes circulation networks, like roads and trails. It includes natural systems and features, the topography, buildings and structures, constructed water features. Vegetation, that's an important one for cultural landscapes. Small scale features, the archeological sites, the cultural traditions. That's one that can be a little bit less obvious on the landscape. The arrangement, the cluster arrangement of things on the landscape too. Views and vistas, and social organization and land use. Some of these kind of overlap a little bit. Landscapes…as small as just the landscape around a house, for example. Or it can be a whole neighborhood, a whole mining district. I think the Lost Horse historic mining district is over 8,000 acres. There's a lot out there and there's a lot of different features that take a while to access because you have to hike to all of them. Well, some of them you can drive to, but it involves a lot of data organization too and keeping track. What we've looked at, where we've been and a lot of research to make sure that we're identifying things that are historic versus things that are not historic. What is actually associated with that period in time. The period of significance and what has been added afterward. The rule of thumb is that if it's fifty years or older, we need to evaluate it for historic significance which the significance can be one or more of the four criteria. If it's associated with an important person in history, an important event. If it has the potential to yield future data, like archeological information or a historic style of design or a method of construction. If it's representative of that, and of course some of these things can, some historic buildings or cultural landscapes can be associated with more than one of these criteria.

Ian: Keeping a comprehensive inventory of all historically significant landscapes is very important to the National Park Service. The information from the service-wide cultural landscape inventory, or CLI, is useful at all levels of the Park Service. If we zoom out to a national or regional perspective, it's useful for planning efforts and budget decisions. On a park to park level, it helps managers plan and prioritize projects and how to spend funds. It also serves as a record of management decisions and helps with informing and enhancing interpretive programs like Joshua Trees Keys Ranch Tour. Now, while the Keys Ranch is a set of historical structures that you actually need a Ranger guided tour to visit, there are an abundance of others located inside the park.

Genna: We have a lot. We have just around 200 that are fully documented, but there are a lot more out there too and for historic structures. We're talking about anywhere from a full building, like for example, the Black Rock Nature Center, which is a young historic building all the way to a small retaining wall that could be along a historic road that is now used as a trail in the park. There are a lot of things involved in maintaining the historic structures in the park. Research and understanding the history of those structures and how they've been maintained to this point is a really important factor in that. And working together with other divisions to try to make sure that we're taking care of these things appropriately. And then also we do a lot of preservation projects. For example, out at Keys Ranch, we do a lot of stabilization work on the fences and the structures. The buildings out there understanding the full history. Why it's there, how it was constructed, what it was constructed with, who made it, and what's changed since it was constructed. Those are all important things to be thinking in informing us about how we can continue to take care of them. And it's all part of the integrity, the historic integrity of these features. The integrity is kind of the authenticity. How accurate is it today to how it was historically for that period of signific.

Donovan: Now, if we had the opportunity to put visitors who come to Joshua Tree National Park into a time machine, we would show them a cultural landscape in its historic state, but we don't have a time machine, so preservation is the next best thing, and that is exactly what Genna is here to do. Her work has allowed us to, well, let's just say change the clock of time.

Genna: There are four treatment types and that's throughout the whole NPS that are called out in the secretary of the interior standards for the treatment of historic properties, and they include preservation, which I also use as the blanket term for all of these. So don't be confused. There's rehabilitation, there's reconstruction, and there's restoration. If you think of these as a clock, that's a good example that they use in historic preservation school, a lot preservation. As that clock is moving forward, we're constantly moving it back to a certain time, and hopefully it's just small adjustments that don't have to happen often. That clock is going to move forward a lot faster, and then suddenly we have to really shift it back. For rehabilitation, we're moving that clock forward a little bit. We're adapting that location or that building to modern uses. Still, this happens a lot when it's a structure that we're building or a cultural landscape that we are using for modern day uses like a visitor center. There are a lot of historic visitor centers in the National Park Service, and they have to be compliant with modern standards for accessibility or for IT equipment, things like that. There are some adjustments that have to be made. Then there's restoration. You're moving that clock back pretty drastically. Restoration is when you're removing those things from the landscape that have been added after that period of significance to restore it to its historic appearance. And then reconstruction. This is where we've completely lost the clock, and we need to create a totally new clock that looks and acts just like the old. So maybe it's lost a fair amount of that authenticity, but at least we still have something that is representative of it. Overall, we use preservation the most, and it definitely depends on the cultural landscape or the site that we're working on. Actually, most of our cultural landscapes are preservation treatment. Even within a building or a cultural landscape, you can have more than one of those preservation treatment types. A lot of times zones will be called out for addressing needs in a certain area. At Key's Ranch we have the visitor access road and then the parking area. And that is an area that we treat differently than the main Ranch complex, which is predominantly preservation efforts, but the access road in the parking area is more of a rehabilitation. We need to have a vault toilet there. We need to be able to take care of visitor needs out there too. We use the preservation treatment on most of the structures at Keys Ranch. We're trying to stabilize existing fence lines or stabilizing the buildings out there for the visitor access to the site. That area where we drive through and park and there's a vault toilet that's not historic. That would be rehabilitation. We don't have many examples, if any, of reconstruction. I think that it's a treatment that is much less frequently used than it was at one time. But for example, out at Keys Ranch, there was an Adobe barn that used to be in front of the machine shed, and it started to collapse throughout the Keys occupancy of the site. It was in pretty poor shape, if not completely collapsed by the time that the Park Service acquired the location. We have chosen to not reconstruct the Adobe barn. For a while, there was kind of a little camper trailer and another little road section that was added to the center of the ranch complex for a caretaker to camp at. That was not historic so that was later removed. That is an example of restoration.

Donovan: Okay. So just to review, we have: Preservation, which is stopping the clock or turning it back slightly in order to view something in its state of historical significance. Rehabilitation is moving that clock slightly forward. An example of this would be bringing an older building up to code for modern use. Restoration is moving that clock back drastically, attempting to restore something's historical appearance. And lastly, reconstruction, which is essentially creating a whole new thing, but it can still represent a particular time in history and its uses preservation adaptations over time, but it must in order to overcome new obstacles and challenges.

Genna: Because we're often trying to mimic the processes of maintaining a structure or a landscape that would've been happening naturally if people still lived there. Say for example, when the keys family was at this location, they would've had animals grazing. Those animals would've been trimming back vegetation because they're eating the vegetation. We don't have as many critters. We certainly don't have livestock out at the park eating that vegetation. We have to go in and mechanically remove some of the vegetation or trim it back so that there's a distance between the shrubs or the trees and the structure.

Ian: However, mechanical removal, as Jenna mentioned, can be a tricky task for areas of the park that are considered wilderness. In many of our heads, there exists an idea of wilderness that offers escape from the bustling development of the surrounding areas. One where visitors are rewarded with dark night skies, amazing views, natural, quiet, diverse floor, flora and fauna, and the opportunities for adventure. As charming as that may be, there's actually a legal definition and method for designating lands as wilder. All right, so here's a quick lesson on wilderness. Wilderness areas are the most protected public lands in America. They were created by the Wilderness Act of 1964, and its newly established category of federally managed public lands. Wilderness can be managed by not just the National Park Service, but also the Bureau of Land Management, the United States Fish and Wildlife Services, and the United States Forest Service. The idea was that wilderness areas would forever be preserved as large roadless tracks where mechanized vehicles and equipment were not permitted, where evidence of modern human occupation would not be allowed. And where future development would not be considered. However, today only about 5% of the entire United States is protected as wilderness. About 85% of Joshua Tree National Park is managed as wilderness. While historic structures that may attract visitation are not generally recommended for wilderness areas, their presence does not make an area ineligible for designation. They do, however, make historic preservation an interesting task to say the least.

Genna: One of the major differences in how we treat those structures and landscapes is just that we can't use mechanized tools out there. We can't access these with vehicles or with helicopters, things like that, unless absolutely necessary. There's a whole process of the minimum requirements analysis that we go through to determine whether or not one of the prohibited uses in wilderness is justifiable. It is kind of cool that it really encourages us to use some of the more traditional construction methods out at these locations too. If we're doing a preservation or stabilization treatment, we're using hand tools, which takes some skill. I don't think that we see as much reconstruction happening in the park service as a treatment, but more of the preservation and trying to just maintain the existing fabric. A historic building or a site, but it is definitely situational. Every historic structure or cultural landscape has a different treatment plan and approach overall, and that there's a lot involved in determining the course of moving forward with those.

Donovan: Conserving these historical structures has adapted over the years, but unfortunately, sometimes treatments or methods can only go so far along with many other fields in conservation. There are several issues these cultural landscapes face.

Genna: There are a lot of layers to this question. First of all, we have just the passage of time and kind of the wear and tear that happens from just general weathering to exposure to things decay change over time and that's kind of the broad catch all. Within that, we have pest management issues. There's a lot of really active termites out here. Other things that we deal with out here are kind of the extreme weather conditions. In a desert, we have an extreme climate to begin with, but then with climate change, everything is accelerating and we're having more drastic windstorms and sporadic torrential rainstorms that can do a lot of damage really quickly. I think in our park specifically, it's kind of challenging to measure the effects of climate change so far because we don't necessarily see sea level rise or something like that, where it's a real obvious measure of that climate change happening. Some of the other things that we deal with are visitors as well. One person can do a lot of damage, whether they know that they're doing damage or if it's completely unintentional. Another thing that we deal with that could impact and does impact our historic structures. The wildfires can also contribute to that…once a fire goes through an area. Then if we get heavy rains, a slope could just completely wash out. Up in the Lost Horse historic mining district, there are a lot of very steep slopes up there and a wildfire went through quite a few years ago at this point. And so, there's a lot of vegetation that's grown back, but maybe not as much as there was pre-fire still. And I was up there just a few months ago and, after a rainstorm, had noticed that there was a lot of sediment that had moved down slope and is now resting against one of our historic structures up there. It's one of those things that could be kind of difficult to notice unless you have a knowledge of that location or information about it; photos, evidence that of what the conditions were. And that's another thing that we do to maintain these sites is monitor the conditions. We are constantly, going back to locations and recording the conditions, looking at whether or not there are impacts to the site. If there were previously noted impacts, like pests or increased visitation to a site, we're looking at if there's a change, if there's new impacts, anything like that, we try to think of all the potential factors that could be affecting these locations, but I'm sure we're missing some. For example, with the issue with termites, generally higher temperatures, maybe the termites aren't going dormant for as long. I'm not an entomologist, so I don't know but it's one of those things that I think about and wonder are there are going to be effects on these things that we're just not thinking of right now, that I don't know about, or that could be really difficult to observe or measure unless there's some sort of specialist out there.

Ian: As we start to get an idea of all the different environmental and wildlife considerations Genna must take into account for her preservation work, it feels a bit overwhelming, but at her core, Genna, like all of us here at Joshua Tree, is an admirer of all life and beauty in the park.

Genna: Look at about the little tiny flowers.

Ian: Mm-hmm.

Genna: It's a lot blooming.

Ian: Yeah. This is actually coming out better than I thought.

Genna: Oh, I can't remember what these guys are called. They're super cool though.

Donovan: We walked around the Keys Ranch for about two hours. The Keys Ranch property where tours are held, sits on 80 acres, but the Cultural Landscape Index recognizes 1038 acres of land that is associated with the Keys family stretching from the Hidden Valley area all the way to Queen Mountain. As we walked through the ranch, Jenna pointed out intricate details that we wouldn't have noticed without her. There, she showed us hidden fixtures added to prevent the wind from opening doors and even the tiniest nails that have been added to keep the wooden planks on their frames. This collection of historical artifacts and structures is an important and complex project to handle, especially with the amount of wood being exposed to extreme weather such as snowstorms, triple digit temperatures, and mighty winds. Yet some areas still look just like the old photographs.

Genna: Yeah. So historically people would've used linseed oil to condition the wood, and it helps protect it from weathering and linseed oil, when used repeatedly, it can have kind of a photo reaction and turn really dark. Now, what we have been trying tongue oil, which is very similar but it doesn't have quite the photo reaction, and so it doesn't turn as dark. And we mix it with the citrus solvent to help paint it onto the wood surfaces, and that helps condition it and kind of breathe some new life into the wood. The schoolhouse and the guest house both have full treatments of a tongue oil application on them. The main house, parts of it used to be painted. You can still see some of that remnant green paint on there, but we have not conditioned the wood on the main house recently. And another treatment that we do on wood specifically where it has contact with the ground is borate treatment, which deterred termites and they help protect from some of the fungus or microbes that could be eating away at the wood, rotting the wood. We did have an issue once where we were putting new glazing putty on some of the windows, doing some preservation work, and we left the windows out on sawhorses, they were totally flat. The next day when we came out, there were all of these little bite marks on the putty, and there were little paw prints all over the glass, and it looked like a ringtail cat had been super curious and gotten into it. which was like, "oh no! All of our work has been ruined." But also, this is really cool.

Donovan: On my tour, I use a photo of Bill Key standing next to the main house to show how well the structure has been preserved. But some other structures, unfortunately, aren't as easy to be preserved. One that is constantly battling forceful winds is the outhouse located near the guest house. This past year, it was pushed over twice by strong winds causing the wood to break and shatter.

Genna: Some material that was already delicate, it can't withstand the forces of the winds that we're having these days. After we tipped it back up initially, that second windstorm came through. Unfortunately, it wasn't secured any more than it had been before and so it fell over again. And now, looking at it now, there's a few boards and some material that we're going to have to replace because it's completely broken and rotted. I think that climate change is definitely a factor here. The accelerated deterioration that can be caused by high winds and extreme weather events that we're seeing more frequently.

Ian: Like the passage of time or the movement of wind across the valley. We were starting to get the idea that these landscapes are constantly undergoing shifts and changes.

Genna: Yeah. Understanding that a landscape is not static, that it's constantly changing. There are those rapid changes where we are constructing things or a fire comes through and drastically changes the what's on the landscape. But there's also those subtle changes over time and in preservation, we're trying to kind of pause that clock and inhibit the change, I guess you could say. But approaching a cultural landscape, looking at it as this place that can really teach us and help us connect with the past that these places represent the history that we might not otherwise understand and appreciate. As a visitor coming to the park, we carry our own experience and our own expectations and our own thoughts on what it is to drive through a national park and see a place. If we go to a cultural landscape like Keys Ranch, we can hopefully think about how the people who once lived here experienced this place; That there wasn't a big main paved road out there. There wasn't cell service outside of the park, let alone inside, which we don't have. There is a completely different experience in understanding and expectations that were carried by the people who lived here.

Ian: Historic preservation offers us a chance to use a different lens and ask ourselves important questions like what is important in our history and what parts of our past can we preserve for the future? However, the lessons we can draw from the field often go further. It can be used as a tool to learn important aspects about ourselves and transmit our understanding of the past to future generations. In fact, Genna's work in the field of cultural landscapes informs thoughtful reflection on teachings from the…

Genna: From the historic preservation perspective, reusing and rehabilitating historic buildings has a lower impact on the environment overall than constructing a new location. I think looking at these historic sites can teach us a lot about living on the landscape with a small footprint. Something that visitors can take home from experiencing these sites is just the self reliance that people have had throughout time in fairly recent history too. I think a lot of the human ingenuity too. It's a lot easier for us to go to the grocery store and just buy some food rather than put in a lot of labor and time and care to grow it ourselves. We don't manipulate the landscape on our own property as much to collect our own water we rely on different sources. It's a part of what makes this place special, and it's unique and it's also very unique that it's being preserved as such. There are things that we might not even think about now that in the future we'll be able to look back on at these places and understand humans and how we've lived, how we've survived, how we've thrived at different times and places. We can look at these landscapes that we drive through in our fast cars on paved roads, and it's easy to forget that not too long ago people were relying on horses and carriages, mules and burrows to get around on these dirt roads or paths. I think remembering our recent history is really important. Part of what makes us human. I think one of the biggest things that people can do to help is to simply observe these places when they're experiencing them, to leave everything as they see it and take photos and take those memories with them. Stop and think and appreciate the place as it is. Take it in.

Donovan: With so many cultural landscapes within the park, it's almost impossible to visit Joshua Tree National Park without coming across one. While these spaces have a lot to offer, it's important to recognize that they need our help. They need us to give back just as much as they have given us to help preserve these historical places and their stories, we must take only photos and leave only footprints. Leaving historical items in their original context is essential to their preservation. Of course, all this talk about Desert Queen Ranch might inspire you to hop in your car and drive there during your visit to the park. But in order to help protect these spaces, it is important to consider what methods are utilized to help preserve them for future generations to enjoy. Rules and regulations are important tools of historical preservation. With that in mind, the Keys Ranch is closed to the public unless accompanied by a ranger. For more information on how to reserve a ranger-led tour, please visit our park's website. Where Two Deserts Meet is an official production of Joshua Tree National Park, co-hosted and written by Ian Chadwick and Donovan Smith, produced and edited by Donovan Smith. We would like to extend special things to Genna Mason Bjornstad for taking the time to talk with us. Sharon Lee Hart for letting us use her artwork titled Split as the Cover Art for Where two Deserts Meet and Bar Stool for their songs. Slow Lane Lover. Lockley Fells, and Feather Soft. For more information about the park and how to reserve a tour, please visit our park website at www.nps.gov/jotr. Happy trails.

In this episode of Where Two Deserts Meet, we connect with Wildlife Ecologist Michael Vamstad. With his insight, we dive into the wonderful world of Joshua Tree National Park’s wildlife, consider the special care that goes into conserving their populations, and discuss tips on how you can help protect and possibly spot some on your trip to the park.

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Donovan:  Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land in which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place and we pay our respects to the people past, present, and emerging who have been here since time in Memorial.

Donovan: Hi, I'm Donovan.

Ian: And I'm Ian.

Donovan: And we're both park rangers here at Joshua Tree National Park. Where Two Deserts meet is a podcast where we investigate topics that often require a bit more detail, and sometimes, the help of an expert in the field to gain perspective.

Ian: Donovan, have you heard any good animal facts recently?

Donovan: My favorite go-to animal fact is that the rattlesnakes that we have in the park smell with their tongues.

Ian: Elaborate.

Donovan: Joshua Tree National Park is home to six different species of rattlesnakes which are part of the pit viper family. Pit vipers have special pit organs that they use to catch prey. Those cute little tongues that pop in and out of the rattlesnake’s mouth help transfer the smells and temperatures of its surrounding. The pit organs are located in the front of the face and they allow the rattlesnakes to sense out the smell and heat of its prey.

Ian: I'll admit that is a pretty good fact, but I've got a few of my own tucked up my sleeve. Did you know the desert tortoise moves at an average speed of 0.2 miles per hour.

Donovan: Okay, but how long would it take them to get to the other side?

Ian: Very clever.

Donovan: I'm sure that both of us can go on and on, but you know who would have even better facts about some of the wildlife here at Joshua Tree National Park Wildlife ecologists? Michael Vamstad. He always has some great insight about some of the amazing animals in this park such as bats, bighorn, and big old tortoises.

Michael: My name is Michael Vamstad and I'm the wildlife ecologist here at Joshua Tree.

Ian: Tree National Park is home to hundreds of different species of wildlife, including roughly 250 different species of birds and about 150 types of mammals and reptiles. As you can imagine, the roles and responsibilities of the lead wildlife ecologists here are very diverse. it's Michael's job to monitor and work with many of these species within the park, but some often require special attention.

Michael: The most common species that I work with, or the ones I spend the most time on, are the endangered species or the species that are of special management concern: desert tortoise, and big horn sheep. Nesting raptors are another thing that every year we spend a lot of time.

Donovan: In 1973, the Endangered Species Act was signed into law creating protections for all plants and wildlife listed as threatened or endangered. This law requires all federal agencies to consult with the US Fish and Wildlife Service to ensure that the actions they authorize, fund, or carry out are not likely to jeopardize the continued existence. Any listed species or result in the destruction or adverse modification of designated critical habitat of such species. That was a mouthful, but essentially, it's saying that there are millions of species on planet Earth and tools like the Endangered Species Act help us better protect species who are at high risk of extinction. There is quite a lengthy process to get a species listed as endangered, but of course, the first step is figuring out what species needs our help.

Michael: An endangered species is simply just a species that has seen its numbers shrink or its habitat shrink. Its numbers are to a point where we're concerned about it being able to self-sustain into the future. A classic example would be the condors or the bald eagle, where DDT thinned their eggs to a point where we weren't seeing very many bald eagles. When they classify the species as endangered, it's really based on their abundances and distributions, when there’s been a big change in reduction. You have fewer of them around and fewer places. The desert tortoise is like the main one that the US Fish and Wildlife has listed for us. It’s the one that is inhabited in the park, the one we spend the most time on. There are a few other species like the yellow-billed cuckoo and the California gnatcatcher and a couple rails that come through the park during migration. There’s not a lot the park can do to manage endangered species, per se, because they're just passing through. We really focus on our resident species that are having a hard time. We have a couple plants that are also endangered, but the desert tortoise clearly gets the most attention from the park to conserve them. We really have some of the best protected habitat for the desert tortoise in the Mojave Desert. We really try to protect the best we can, and then keep our millions of visitors away from affecting them negatively in any way. The populations of desert tortoise have really changed in Joshua Tree since like eighties and nineties. During that time we did some very light surveys to get an idea of abundance or how many of them were on the landscape. And it turns out there’s anywhere between thirty or forty, or sometimes even close to fifty tortoises counted per square kilometer. Nowadays when we do those surveys, we're only finding three to four tortoises per square kilometer. So going from thirty down to three is a huge change. And as a scientist, we call that an order of magnitude reduction. That means usually like a tenfold reduction. And there's really little that you can argue about that kind of change. A lot of scientists, we look at different survey methods. Each survey method is a little different, so your numbers can be a little different, but when it is an order of magnitude change, thirty down to three, it's kind of undeniable. At that point, historically, we had pretty good populations in the park and we probably had close to 30,000 tortoises in Joshua Tree. And nowadays I estimate about 3000 tortoises. We've been a putting these little radio transmitters on the back of tortoises. What that allows us to do is to go out once every couple weeks to see where they're at and to see how they're moving on the landscape. Do they move miles at a time or do they just move a hundred feet at a time? Do they keep a same home range over the years, or do they really change and move around? And so, what we're trying to figure out, how can we get an idea of the movement patterns for those tortoises that live by roads? Is there a way to work with our million visitors and all that traffic on our roads to keep the tortoises from getting smashed on the roads? For example, during rainstorms, we've found that they tend to go towards wherever the water is. This can be the road. We have signage at each one of our entrances that tells people, “There’s a rainstorm right now. Please watch out for tortoises on the road. Those rocks on the road may not be a rock, but a tortoise drinking water. Additionally, we have tortoise crossing signs in the park that make people aware that tortoises are there and to drive slowly to avoid hitting them. That really is the biggest issue that we have.

Ian: The desert tortoise was added to the federal endangered species lists in 1990 after a significant reduction in their numbers was observed over the past few decades in Joshua Tree National Park. Estimates from past research indicate there were approximately thirty tortoises per square kilometer. However, there is now an average of roughly three tortoises per square kilometer. That's a massive 90% reduction of the population within. Tortoises that were once abundant roaming the desert and a relatively common site are now something you need to be lucky or diligent to find.

Michael: Yeah, the big reduction that we saw from the late eighties and nineties to now. We believe had two big issues that happened at the same time, and they worked together synergistically and negatively. An upper respiratory tract disease was introduced to the desert tortoise sometime in the late nineties, but we think it didn't get into the park until the early 2000s. What happened is that they basically get a really bad cold during a time when they need to conserve. Imagine having a really runny nose from a chest or a head cold, but you couldn't drink water to hydrate yourself. These tortoises were dying from the disease. This was coupled with drought. We’re also seeing these recurring severe droughts happening in the Mojave and we really believe that's from climate change. The effect of climate change is more severe droughts. And then you have this disease issue going through the population at the same time. Those two things working together reduce the tortoise population in the park. We believe the disease came from a pet tortoise or a tortoise in captivity that got introduced into the park. It's not a native bacterium that got into the tortoise. We've seen it in other reptiles and predominantly within the pet trade of tortoises across the globe. The mycoplasma agassizii, which is the name of the bug that got into the tortoise here in the Mojave, was really derived from other mycoplasma and bacterium from around the world.

Ian: Michael brings up a great reminder here that the wild desert tortoises that we have inside the park shouldn't have play dates with any pet tortoises you may have at home. It's nothing personal. They just don't have the same immune systems, and honestly, they are quite the homebody anyway. They're small population numbers in the park. Paired with their homebody behavior of spending most of their life underground, can make desert tortoises come off as quite aloof or mysterious. Because of this, they're often one of the most asked about species by park visitors. However, as exciting as it can be to see one, it's important to remember to respect their personal bubble and keep your distance.

Donovan: While tortoises are definitely a fan favorite among park visitors, a species that always stays neck and neck with the tortoise for most sought-after sighting is the big horn sheep. Some people might also know them as rams, but the term ram actually refers to a male big horn sheep with the iconic curled horn. On the other hand, female big horn sheep are actually called ewe spelled e w e. Bighorn sheep are one of our larger mammal species that we have inside the park, but honestly, there is something very magical about getting to see one in the arid desert. One could easily fall for the misconception that since they are large, they should be easy to find in the park. However, they are impressive experts in camouflage and do their best impressions of the beige granite boulders in the park by employing a similarly colored coat and often remaining quite still while out and about. With the massive size of the park, this means that visitors are often playing a very difficult game of hide and seek with big horn sheep.

Michael: Big horn sheep in Joshua Tree really are a very difficult species to find. You'd think because they're pretty big they'd be pretty easy to find, but they are rock dwelling creatures in some of the most rugged and rigorous habitats in the park. It’s very difficult to count them or to get a real good understanding. But we do see them during certain times of the year. They need to drink open water, mainly in the hottest months of the year. In July, August, even into September, we see them around water sources. When it comes to viewing them or finding them, or for us to count them, we try to go in the summertime to these places. We set up cameras to take infrared triggered photos with these wildlife cameras. Really interesting stuff. We know that their populations really expand and decline, and the literature really reflects that. When mountain ranges in the Mojave get a really good monsoon or good winter rain, the forage is really good, but then another mountain system, literally 10, 20 miles away may not get any of that. The sheep that are in those mountains having a really hard time generally don't expand, but the ones where they got the really good rain, do expand. The lambs are born very well. They’re super healthy. They ewes are providing quality milk to those lambs so they're able to survive. Whereas the sheep that are in those mountains that are in less than ideal, they may not have any lambs that survive. It really is dealing with the conditions of the land in Joshua Tree. We've had a couple of issues. Everything seemed to be rolling pretty good when times were good. The sheep were everywhere. But we also had disease come in too. Just four or five years ago, we identified a strain of mycoplasma. Again, you probably heard that's from the bacterium that the tortoises had. The same similar bacterium is actually in bighorn sheep causing very similar issues, upper respiratory distress. They lose a lot of water though basically mucus and other things like that, and it makes it really hard for them to survive. The adults generally can get over it, but the lambs succumb to it almost a hundred percent of the time. Very, very few times do we see a lamb that gets sick from the disease that makes it through. Conditions are just so hard in the summer, and if they get that sickness, they don't survive. It also highlights the importance of connectivity in the sense of looking at the desert. Areas that got really good rain, got good plant response, therefore really good forage for the bighorn sheep. But then this range over here doesn't. In the past, when there weren't any highways in between or any solar fields in between or other things that humans development that prevents that movement, bighorn sheep were able to move in between different herds and repopulate from good, healthy herds over here to repopulate the herds that were struggling. That’s called a metapopulation dynamic. It was originally described for butterflies. Where resources would be really good in one area, the butterflies would do really, really well one year, but in another area they would all almost go extinct. That is a big challenge with the bighorn sheep management. We know where these connections between large land masses for the sheep have been fragmented.

Ian: Often when discussing the topic of big horn sheep visitors will mention sightings at other park service sites such as Rocky Mountain National Park. While there is some uncanny resemblance between the sheep here and there, the ones in Joshua Tree often appear much smaller in size. On top of that, they will often behave differently, but that makes sense when you take into account the harsh and dry climate of the desert compared to the cool and mountainous areas of the Rockies.

Michael: The bighorn sheep in the desert are called the Nelson's Desert Bighorn Sheep. That’s actually their full common name, and they are quite different in size and even coloration than the Rocky Mountain Bighorn sheep which you tend to see in Colorado, Northern Nevada, Montana, some of these other places with the Rocky Mountains. They tend to be bigger, bulkier animals. And when I drive through that area of Colorado and I see sheep along the side of the road, I'm always taken back like, wow, these guys are big and they're heavy. They're called the Rocky Mountain sheep because it is a different subspecies of Big Horn, but they are all ovis canadensis. Which is basically big horn sheep. It's just a subspecies difference so the sheep down here in the desert seem to be more adapted to desert environments. They're lighter colored and not quite as large. They don't have the water requirements that the rocky mountain sheep do. They've even learned interesting adaptations like kicking over cactus and eating out the innards of a cactus. So there is a bit of a difference between them, but not as much as you would think. The sheep that are below Interstate 10, basically Palm Springs south into Anza Borrego and down to the Mexican border, are considered the Peninsular big horn sheep. At one time, they had called them a separate species of sheep, but later on, through genetic work, they found that they are pretty much identical to our desert bighorn sheep that we have here in Joshua Tree. They continued with their listing of them being endangered, not the ones in Joshua Tree National Park, but just across a valley, south into the Santa Rosa Mountains and San Jacinto mountains and Lagunas. These sheep are endangered. They're covered under the Endangered Species Act. They're listed, but they're more of a geographic range. They said all these bighorn sheep that are in this area have really suffered from development issues, basically losing connectivity as well as numbers reductions from disease. They continued with that endangered species protection for just that population. In every other sense of how the animals act and how they deal with the desert is very similar to the ones in the in the park.

Donovan: If you've ever recreated outdoors before, you may have come across a closure of an area for reasons related to wildlife. National Park Service sites like Glacier will sometimes close trails due to bear activity or climbers at Devil's Tower may find the climbing route that they were eyeing up is closed for Raptor nesting. But if you come to Joshua Tree in the summer you'll find something a little different. Often during the consistent triple digit temperatures and extreme sun of the summer, Joshua Tree will close a specific trail on behalf of our beloved big horn sheep. But many often ask, what is the purpose of these closures and how does the park go about deciding how and what to close?

Michael: Closing down areas in a national park for wildlife is definitely a decision we don't take lightly. Any and every option or alternate to thing to try is considered. We look at the amount of water in the park, especially related to bighorn sheep because they really need it. In the summertime, we've monitored our water sources in the park and when we're in a severe drought and we lose those water sources, we count them. I created a decision matrix that would be completely rigid once these places go dry, then we go ahead and close down areas to visitors. The idea here is to only close the areas when they are needed by the wild. In this sense, when the drought is severe enough that it's removed water from Barker Dam, Keys Ranch Dam, and few other places, we assume that these other places where they get water are dry as well. For example, the Bighorn Sheep closure at 49 Palms Canyon is something we don't do every year. Five years ago we did a closure and then for three or four years, we didn't do any kind of closure. However, the last two years in Joshua Tree have been extremely dry, and so these other water sources that were once available for the sheep are now dry. We go ahead and close 49 Palms Canyon because it’s a real perennial permanent water source where the spring is always running. It seems to always fill up pools of water and it never dries up. In July and August, our visitation has gotten to the point where if we did leave it open, we would have visitors there every day. And that would displace the sheep during the most critical time for them. We go ahead and close those areas, so we definitely take it very seriously. We do not like to close down areas to the visitors but what's been really cool and really heartwarming for me is that whenever we put out these public announcements that we're going close 49 Palms Canyon…it is overwhelmingly positive. The folks that comment on that stuff, on social media or even on our website almost, 90 percent of the time, it's actually very positive. They're happy that we are doing this for the sheep, so that makes it really easy for the ecologist.

Ian: Of course, monitoring big horn sheep access to resources in these areas is a big deal. In order to get the best results, Joshua Tree National Park had to take a critical step in building an understanding of big horn sheep, and that's by collecting.

Michael: The park decided to put forward a proposal on a project about three or four years ago to put these collars on bighorn sheep, and it literally is like a necklace that we put on the sheep. Everybody, I think, can imagine what a collar looks like. We went out and we collared sixteen animals and the idea there is that these collars send data to the satellites. I can even look on my computer, my laptop right now, and check it out. Where are the sheep now? And we put those collars on the animal to really see what habitats are being used. Are they going into areas that has a lot of visitor interaction? The real Hidden Valley, for example, has thousands of visitors every year. Or are they choosing habitats that are very rugged and don't see visitors at all. We're almost at the end of that study. We're still collecting data but what we are seeing is that few places are very important to Bighorn sheep. They go there a lot, they hide. I think it's a lot of predator evasion at that point. If they hang out in these locations, then they don't get predated as much by Mountain Lion. We have really cool data on our visitors as well. Where are they going? We set up trail counters. Barker Dam, for example, had 550 people on the trail today. Then we look at how many times the bighorn sheep are in those areas when they have that many people around. This is a second time we've looked at this. We looked at it back in the late nineties, and we found really interesting things. On weekends, the bighorn sheep would avoid these areas with a lot of visitors but the instant it became quiet, let's say on Monday or Tuesday, they would go back into these areas. Now that was back in the nineties. When basically we had under a million people, I think it was 800,000 visitors or so. We are really concerned about this expansion of visitation in the park to almost 3 million visitors. And would they then have that persistent, constant, presence at these areas instead of like before, whereas only the weekend was busy. Now we're starting to see the weekend and the weekdays busy even in the summer. We are really concerned about that increase in visitation and that effect it could have on the sheep. The technology is that these collars talk to the satellites. I can see it on my laptop, and we can see these movements and shifts in their patterns and how they use the habitats when there's a lot of people, or not so many people. We're really trying to really focus in on how the big horn sheep really get affected by visitation in the park or visitors walking around. For example, if there was a time period where they're lambing. The pregnant ewes really like to go into areas that are secluded. They're solitary, they're by themselves, but they're very in tune to those sites, they going back to them yearly to lamb in the same basic locations. We really want to figure out where are those locations. In the future, if we're talking about putting in a trail or something, or back country camping area, we are going to make sure that it's not in those areas that the sheep are lambing, it's just too important of a time for them. So that's one of the ways we're using this technology to guide our management into the future.

Donovan: As we've already stated, ensuring adequate water for the big horn sheep is a very important part of the conservation process here at Joshua Tree National Park. But that's not the only adversity that big horn sheep face.

Michael: There really is a problem with pets in parks and pets really are close to us. We love them. Personally, I have a dog. There are certain areas of the country or certain places that I just will not take my dogs and national parks are one of them. They really do have an effect on wildlife and everyone that brings their pets to the parks or to these areas should really be aware that they can have a real negative effect on big horn sheep and desert tortoise and things like that inside the park. Other national parks have the same problems. The marmots and pikas on in Rocky Mountain National Park is another place where these critters are just walking around the trail and then someone with a dog arrives. And all of a sudden, all those critters take off. Wildlife understand and really know when there's a predator in there. Dogs and cats and things like that are instantly known by wildlife as predators. The fact that your pet may have been in an area will displace things like bighorn sheep. They'll smell either the leavings or droppings from the dog or cat, or they'll basically be scared of the barking or other things like that. We want people to enjoy wildlife. Pets, however, in these areas, prevent that. There’s further issues with even things like disease. One example that we had in the park where it was particularly bad is that we had canine distemper go through a population of fox and we're finding dead fox all throughout the park. The issue here is that canine distemper can be carried by your pet and brought into the park into an area where animals are not vaccinated against that. The fox aren't given shots every year by veterinarians to prevent things like parvo or any of these other diseases that are common in our pets and treatable. The wildlife aren't treatable so when we find that there's a problem, it's usually because there's a bunch of dead ones. Let us be a visitor to these areas as well. We go in, we enjoy it, and we leave. Because the primary focus of these areas is the preservation of the natural and cultural artifacts in these areas. I really truly believe, let's give wildlife a rest or some reprieve from pets.

Ian: When discussing how our pets and other actions we can take, while visiting can affect the chances of seeing rare wildlife. It's important to remember that those aren't the only species that a wildlife ecologist will work. Sometimes a more common species of animals, visitors will see in the park can actually be a unique task for a wildlife ecologist simply because their management overlaps with other park objectives. Bats are an extremely common site for those staying into the night to cam or stargaze, and they are an important part of Michael's role here.

Michael: We have some really interesting species of bats in the park as well as abundances. It's actually quite interesting. Our most numerous bat is called the canyon bat. Used to be called the Western Estro Bat. And so if you come to Joshua Tree National Park and you're looking around at night, maybe you're camping in one of our campgrounds and you look up. Very frequently you'll see hundreds if not thousands of bats flying around. What's really cool about these canyon bats is they live in the cracks of the rocks and other places, even trees they'll roost in, but they're definitely our most numerous species of bat in the park. The other really interesting species we get is called a yellow bat. These yellow bats live in palm trees only, which is actually really kind of cool because we have Palm Oasis in Joshua Tree, so the bats are up in those skirts that live underneath those palm trees. They're a bigger bat, but they are yellow and they're really interesting. The other third dynamic or kind of situation that's kind of interesting to Joshua Tree is the abandoned mines. We literally have hundreds of old abandoned mines that were once part of the gold and silver prospecting era in the park. We have a rich history of mines in the park, places like Desert Queen mine. The problem is that these mines are dangerous. These mines are not natural. They were put in by people back in the early 1900s looking for gold and silver but the bats found them and made them their homes. For visitors to the park, I would say, enjoy these mines when you come across them. They're definitely a rich history for the park, so enjoy it but be really careful around these mines. People fall in them all the time, and it's usually a pretty serious situation, getting them out. We put bat gates over the holes, down the shafts in these mines to keep people out or keep them safe, but allow the bats to fly in and out. So that's a fun program or project in how we're making the landscape safe, but we're also allowing that habitat that they've found.

Donovan: A special quality of Joshua Tree National Park I personally love is when camping in the park. Bugs are often not an issue. Of course, the dry desert climate can be thanked for that, but bats also deserve special appreciation when it comes to balancing insect populations within the park.

Michael: The bats in the park are really numerous. We find a lot of these canyon bats at night, especially in areas like Barker Dam or Hidden Valley and in some camping areas too. They eat a lot of bugs at night. You think the desert doesn't have a lot of mosquitoes but there are, the bats are very important at balancing that. We would have huge insect outbreaks in the park if we didn't have all these thousands of canyon bats basically taking away the problem for us. They are also known to really process those dead insects and basically their feces are very rich in minerals and nutrients. Bat guano was once used very heavily for fertilizers for people's gardens and things like that. We've now gone to more synthetic things like Miracle Grow, but back in the day it was bat guano. Bat guano is very rich, high-end nutrients and minerals, and it really helps plant and is part of that whole nutrient cycle of things. Bats are definitely something we watch for. And in fact, one of the things we do in the park is monitor for white nose syndrome. We set up bat nets, which is really interesting at night, at a few places in the park and, capture the bats, handle them, and swab them for white nose syndrome. Now, I must say that, handling bats is definitely something you have to do delicately. They have very sharp teeth, it's very interesting. But they also carry rabies. All of us are working with bats in the wildlife branches here at Joshua Tree have rabies vaccines so that we can handle these bats safely. If you ever see a bat flopping around, you probably heard this before, leave it there. Contact a ranger. Contact your local wildlife officials. That may be the sheriff's department, even in your community or animal control. It's very important that we figure out if the bat was sick from white nose syndrome or something. It's very important to report wildlife doing interesting things or wildlife doing very abnormal things like a bat flying around during the day, but landing nearby, acting all funny is something to be concerned about and you should report it. Really local to this area or in to Southern California is palm trees. And, palm trees are very important for bats. Those yellow bats, like I mentioned before, use those skirts underneath the palm trees. If you do have palm, resist that feeling to clean it up and chop down all those dead, branches that we call the petticoat that hangs down. If you leave that petticoat, you'll actually be creating wildlife habitat for bats. I’ve been trying to figure out a way to use bat boxes that are popular in the Midwest and the East Coast but they don't seem to work out here in the desert. We've tried them a few times. They either get too hot or, for whatever reason, don't work. Another thing with the mines and the caves, if you're visiting them, if there's bats in those caves, they may be displaced. You walk in during the middle of the day and all of a sudden the bats all fly out. Obviously those bats are going to have a bit of a hardship. They're going to have to find a place to roost really quickly, and that may be near predator or something like that. We do ask people to stay out of mines as much as possible. Enjoy them within the landscape…take a look, but don't go inside them.

Ian: We've clearly established that Michael plays an important role here at the park from managing wildlife species to collecting data and making important decisions. However, he's not alone and, like many things in the National Park Service, it's a team effort. Managing wildlife in a national park is quite diverse.

Michael: We count species, we watch over species, but we also monitor the general health of wildlife. But to be honest, I heavily rely on our partners in the USGS that do a lot of our research on disease or research on population Issues, but also disease labs and veterinarians within the park service and the state of California. I'm always sending samples around from one place to the next. I can't be an expert of all these things like disease and pathogens. But what I am very good at is I can get those samples to the lab to do that. Really what I have in my role here at Joshua Tree is to be able to understand all of the science, all of the disease issues, and all of those things that I learn from others. Yeah, wildlife management is really fun, but a lot of times in the park it's, I'm collecting the samples, I'm finding the dead animals on the landscape or something that's happened and I'm reporting that to the folks that can study that. A perfect example of this would be our distemper outbreak in foxes. We were just going out to check a wildlife camera out in the Coxcomb Mountains and, oh, look at this! Two dead kit fox very near the water source. That was a concern. And so, I called up our wildlife veterinarian in Colorado and told her about it and we said, okay, let's go back out there and collect an animal. Lo and behold, when we went back out, there's two more dead kit fox in that area. We collected one, we sent it off, and found out it was canine distemper. A big part of my job is actually these partnerships and collaborations with researchers around me that can answer these things for us. It has to be collaborative. You can't just work in a vacuum and manage wildlife at Joshua.

Donovan: Whether it's leaving the buildup of dead palm fronds, also known as the skirt on the palm trees, to help provide habitat for bats or not taking your pets on trails to preventing big horn sheep from getting sick or even driving the speed limit to keep desert tortoises safe from getting struck by vehicles…there are many behaviors that we as visitors to this place can do to help wildlife populations, but there is a bigger issue that will need us to go beyond individual action in order to help Joshua Tree National Park’s wildlife.

Michael: The effects are starting to weave into so much of our management in national parks. What we're really seeing is changes in vegetation. I would have to say that with the changes in vegetation, you have changes in wildlife. And we're starting to see this now, we're starting to see certain species of birds moving up an elevation where they just can't survive at areas that have lower rainfall or they're experiencing more droughts. We're really seeing a bunch of issues in the park with shifts in wildlife where they're living. Even recruitment of certain plants, elevations that they once could grow, now they can't. But it is starting to get woven into every single one of the decisions around managing wildlife is this kind of unknown factor of what climate change will do. We have predictions, we have models for the park on different wildlife species. We have desert tortoise models where we've looked at climate change effects and pushed temperatures up and then these models tell us…they're not going to live in these big areas anymore. They're going to live in these smaller areas instead.

Ian: As the natural world changes around us, our relationship with wildlife shifts and changes. In turn, people worldwide have a variety of reasons for caring about wildlife. And it holds meaning in multiple contexts and cultures, whatever reason draws you to the natural landscape in hopes of spotting something alive and wild. It's important to remember that experiencing sightings of wildlife means you must pay attention. Turning on your listening ears and using your watchful eyes, paying attention to the world around you is an important way to show appreciation and love for our natural environments. And learning to pay attention can teach us a lot about a unique and special place.

Michael: Joshua Tree National Park watching wildlife in the desert is actually quite difficult. And that is just because deserts don't have a lot of abundance. Let’s say you're going into Olympic National Park up there where it's basically Pacific rainforest, you have a huge chance of seeing wildlife really around any bend, look over a rock, or under a log and you’re going to see something. In the desert, you need to be quiet, looking around, looking at your feet, looking out hundreds of yards and taking it slow. The other thing I would say is it really depends on the time of year. If you're going to be out in July and August the middle of the day looking for wildlife, you're going to have one heck of a hard time because, guess what? You're going to be the only one out in the middle of everything, in the middle of the hot day. Everything else is going to be down in their burrows or hidden or someplace where it's cooler than sitting out in the sun. So, timing is everything. In the springtime, in the desert, especially in Joshua Tree, when there's a wildflower bloom and all that's going on…that’s a really good time to see wildlife. There's a lot of things moving. Early morning hours and early evening hours. These are times when most of our critters are doing most of the foraging or feeding or whatever it might be. They limit their activity during the day. I would say, if you want to see a lot of wildlife in Joshua Tree, come in the spring and fall. Get up early and look for those critters moving around in the early morning and then the early evening. And you'll be surprised on the amount of wildlife that'll be running around.

Donovan: As interpreters, we want our visitors to see as much wildlife as they can while visiting the park. Honestly, nothing is better than getting to hear a junior ranger story of a kangaroo rat in their campsite, or a lifelong traveler's first encounter with a bobcat crossing the trail, and I got to say, I'm the same way.

Ian: I also wanna see those amazing creatures, but to ensure the chances of these sightings, we must make sure the population of wildlife within the park remains healthy. I always think of the words of scientists and author Robin Wall Kimmer: “to love a place is not enough. We must find ways to heal it. Healing and ensuring wildlife wellbeing can be the actions you take during a trip to Joshua Tree National Park, but can also be what you do within your own homes and.

Donovan: Exactly. And while in the park, there are a few easy steps that you can take that you've probably heard of before. Things like making sure that no trash gets left behind or driving the speed limit and not taking any pets on trails. Although many factors that are affecting wildlife that Michael mentioned might feel as if they are out of reach of change, but we have to start somewhere. Good practices of respecting wildlife while visiting the park and at home are just some of the many actions to lower our impacts.

Ian: Exactly. And sharing what you learn and continuing conversations is critical.

Donovan: Speaking of sharing what you learn, while working on this episode, did you learn any new animal facts in the process?

Ian: Uh oh. This again? Alright. It is probably that the desert tortoise can hold its bladder for over several months in order to combat periods of drought. Honestly, I can't even fathom living like that. Since living here, I've always subscribed to the stay hydrated lifestyle.

Donovan: Okay. Alright, well I guess we'll end on that. Have patience, be curious, and keep learning and stay hydrated apparently.

Donovan: Where Two Deserts Meet is an official production of Joshua Tree National Park, co-hosted and written by Donovan Smith and Ian Chadwick, produced and edited by Donovan Smith. We would like to extend special things to Michael Vamstad for taking the time to talk with us. Sharon Lee Hart for letting us use her artwork titled Split as the Cover Art for Where Two Deserts Meet and Bar Stool for their songs, Slow Lane Lover, Lanky, Lockley Fells and Feather Soft. For more information about the park, please visit our park website at www.nps.gov/jotr. Happy trails!

In this episode of Where Two Deserts Meet, we chat with Physical Science Technicians Stacey Manson & Megan Richie. Together, we examine what makes the night sky so special, what we can do to better protect it for future generations, and how to best take it in while visiting Joshua Tree National Park.

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Ian:  Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land on which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place. We pay our respects to the people past, present, and emerging who have been here since time in.

Donovan: Hi, I'm Donovan.

Ian: And I'm Ian.

Donovan: And we're both park rangers here at Joshua Tree National Park, where two deserts meet is a podcast where we investigate topics that often require a bit more detail, and sometimes the help of an expert in the field to gain perspective.

Ian: I got to say Donovan, don't you think it's fascinating that out of all the visitors that visit Joshua Tree National Park, most of them don't even see the other half of the other half.

Donovan: You mean like the south end of the park?

Ian: No, the other half of the park is after dark.

Donovan: Oh, you're right. I guess it is a bit strange, at least for me, since that's actually one of my favorite things here at Joshua Tree.

Ian: Yeah, the dark night sky that can be seen in Joshua Tree is so spectacular. In fact, the park is actually an international dark sky park, which essentially means that Joshua Tree National Park possesses an exceptional or distinguished quality of starry nights and a nocturnal environment that is specifically protected for its scientific, natural, educational, cultural heritage, and for the public enjoyment.

Donovan: Especially the summer Milky Way that's visible during the new moon phase of the lunar cycle really expresses just how dark the night can get out here.

Ian: Oh yeah. I always like to remind people that one important piece of information to keep in mind when trying to plan your trip around the great night skies is check that lunar cycle. Coming to the park on a full moon versus a new moon can make a world of difference with your star visibility.

Donovan: Don't get me wrong though. Visiting the park after dark during a full moon is still great too, because to me that means that the moon will be bright enough that you can see the rocks in the Joshua trees even after the sun goes down. Especially, it's a great time to experience our nocturnal wildlife.

Ian: Ooh, yeah, A bit of a loony experience, you might say.

Donovan: Okay. Yeah, but, well, it's just something about getting to experience the night sky with the Milky Way gasses and those purples and blues covered by trillions and trillions of little glowing orbs with the occasional shooting star crossing your site. That's just really extra spectacular.

Ian: You know, I'm glad we're talking about this, Donovan. It's a good time because with the end of summer approaching a various special event is coming. The Joshua Tree, national Park Night Sky Festival.

Donovan: I love the Night Sky Festival.

Ian: Ah, yeah, same, same. The Night Sky Festival is an amazing event with astronomers, telescopes, stories, and excitement. So as we are getting ready for that event, I figured we could do a little research ahead of time to prepare for what we'll see.

Donovan: Well, you know me, I love to prepare ahead. I'll call Megan Ritchie and Stacy Manson and see if they're available to chat. They are super helpful with all things night sky.

Stacy: Hi, I'm Stacy Manson and I'm a physical science tech here at Joshua Tree. My job duties consist of monitoring three air quality stations, ten portable weather stations, monitoring groundwater, soundscapes night skies, and mitigating abandoned mine land hazards.

Megan: My name is Megan Richie, and I am also a physical science technician here at Joshua Tree National Park. I assist in natural resource monitoring, including our air quality, drilled water wells, weather stations, soundscape, dark night skies, and closing abandoned mineral lands.

Donovan: I think it's safe to say that Megan and Stacy have a long list of duties that they're in charge of here at the park. Something that was clear during the interview was their love for what they do and what inspires them to help conserve our night.

Megan: Viewing the dark sky. I had to have been around eight years old and my parents, you know, I grew up in a mid-sized city, but they woke me up in the middle of the night. We grabbed our sleeping bags and we laid out on the deck. And my memory, if my memory serves me right, I just remember looking up and just seeing meteors or flashes of light. I didn't really understand what I was looking at, but that was my first experience with the night sky. And then coming here to Joshua Tree, seeing the Milky Way for the first time, because growing up in the Southeast you don't see the Milky Way. But coming out here, I couldn't keep my eyes off the sky. I think it's a very personal experience. It's special and everybody experiences it differently. It's something that I feel that can connect you with your present, your past, and your future. I think it's just beautiful.

Stacy: For me, I think the moment that I fell in love with the sky was probably even before elementary school. Very young. My parents had a balcony off their master bedroom and they would set up a bed for us. They would take a mattress out there with sheets and blankets. Myself and my four siblings would all go out there and lay on this bed and just watch the night sky. It was a way for us to bond together to be amazed by the sky above us, to watch meteors, to just watch stars, look for constellations. It was so important as like a family unit to have that bonding experience. That kind of cemented my love of the night Skies.

Ian: So as we mentioned earlier, Joshua Tree National Park is an international dark sky. Which doesn't just mean you can see a lot of stars at night. There is also a sort of community effort going on in order to give you that experience. Stacy and Megan play key roles in working through each requirement for that designation.

Stacy: To become an international dark sky place, you first must have a group of people that are actually interested in protecting a nightscape. People that want to see the stars. Certification involves creating lighting policies, rehabilitating poor quality lighting, educating your neighbors visitors, and about the importance of why do we want to protect our night skies. And then you also must commit to that conservation effort. It's not just one and done, it's a continual commitment to protecting night skies. Park staff have been working on the certification process for years long before I even started back in 2006. The park had to inventory outdoor lighting, retrofit the poor lighting, create a lighting management plan to ensure proper outdoor lighting in the future, and then also document the average sky brightness in the park throughout different areas in the park. We also worked with community members to protect the night sky. There's been a long effort to work with the San Bernardino County to create lighting ordinances that protect the high desert communities. The park continues to educate the public about the importance of a dark night sky and participates in annual night sky festivals hosted at Sky’s the Limit Observatory in Twentynine Palms, CA every year. The park also has to submit an annual report that highlights our commitment to conserving the dark night skies in Joshua Tree. I think one of the reasons that you see that some places are dark night skies and some aren't, is some places have darker skies and you already have people that have been there for a long time going to these places to view the night skies. Places like Los Angeles, where you have a lot of artificial light and there's not a whole lot of stars to be seen, you don't have a whole lot of people living there that are like, “oh man, I wanna protect the skies,” because they just don't know those skies exist.

Megan: Yeah, and I'll piggyback off of what Stacy was talking about community engagement and just getting people outside at night and experiencing the dark sky and getting them excited and passing on their knowledge that they learned to keep our certification up because we want to protect those stars. The East Coast is littered in artificial light, but the West coast is something that we can still protect those dark skies.

Stacy: When Joshua Tree got its certification, The International Dark Sky Association was designating places on a tiered system. You had bronze, you had silver, and you had gold. Gold was like almost perfect, dark night sky, complete absent of artificial light to bronze where you could still see a decent amount of stars but there was also a lot of artificial light in the area. Joshua Tree, on our Western end, we actually meet more of that bronze criteria, but on the eastern end of the park where there's almost no communities out there, it's in the remote desert, we, we almost met the gold standard. We were able to combine those two to designate ourself as a silver tier park.

Donovan: The beauty of the night sky here at Joshua Tree National Park is that people travel from all over the world to see it. But why is that? Why do we not see the same dark night skies in our own hometowns, especially if we live in high populated areas such as big cities?

Stacy: The ability to see stars does vary based off your location. More rural areas, you're going to see more stars. More urban areas, you're going to see less stars. The reason for that is artificial light. Artificial light goes up in the atmosphere and scatters and creates that kind of blanket of light and it dims the stars so you're just not able to see them. Areas like Los Angeles where there's very large amount of people with a lot of lights on, you're just not going to see as many stars as you do here in Joshua Tree where you have much smaller communities.

Megan: I'm from a mid-size city in the Southeast, and one of the first things I noticed when I moved to the Joshua Tree area is just how dark it is out here. I had truly never experienced that kind of darkness. Like having your hand in front of your face and not even be able to see your hand. And I think bouncing off of what Stacy was saying is not only just the lights, but out here in the desert, we have what I call 360 degree view of the sky horizon to sky horizon. A lot of cities have tall buildings and even other rural areas have tall trees. It really obstructs what is straight up above you. What's really unique and special about being out here in a rural desert is that the sky is the limit. You have such a huge canvas of stars up there and it just makes this area very special at night. And it draws quite a good people out here.

Donovan: The general rule of thumb is when looking for a dark night sky, no matter where you're at, the farther away you get from light pollution, the better your visibility of the stars will be. This experience is because of our natural biology. To keep it simple. As our eyes adjust to the dark, they start to create a chemical called rhodopsin which helps our eyes see in low light exposure. Bright lights can bleach the rhodopsin. An example of this would be when you're walking down the street at night and a car drives by with their headlights on, and it might make you feel like you've been blinded momentarily. It often takes several minutes before your eyes are able to readjust again to the dark. Yes, bright lights can affect your rhodopsin, but red light is actually a great tool used by astronomers because it doesn't bleach your rhodopsin. This is mainly because the length of the light waves is much longer. Unfortunately, though light pollution isn't the only thing that can hinder your view of the night sky, other forms of pollution can obstruct our view as well. Light pollution at night is a big contributor to not being able to see stars, but there's also air pollution.

Stacy: Just like during the day, as you mentioned, you'll be in a valley and you're looking across the way. If the air quality's good, you can see the mountains on the other side of the valley very clearly and crisply. But then you'll notice on some days you'll be standing in that valley. When you look across, the mountains are hazy. You may not even be able to see the mountains or behind the mountains. You'll just see the foothills of the mountains. That's because of particle air pollution. We call it particulate matter pollution. What's happening is similar to what you see during the day as the light hits particles and scatters. The more particles you have in the air, the more that light is going to scatter. So just like during the day, at nighttime, starlight and artificial light gets scattered by that air pollution by those particles, and it makes what we call sky glow, a kind of dome over the city where light is trapped. So, air pollution is a big factor in our ability to see stars at night.

Megan: Yeah. our little desert town is growing. We live, walk, and drive on sand, stirring it up. These sources of fugitive dust might seem something small, but when you have these big open areas where they are developing pretty rapidly, it contributes to the bigger haze in the area and therefore obstructs our night sky.

Donovan: Believe it or not, we aren't the only species that needs a dark night sky. Since the beginning of time, plants and animals have adapted to be reliant on the night sky, and a few of those adaptations are still visible in the park today with Joshua Tree National Park, encompassing two desert ecosystems. The plant and animals that live within the park are no strangers to harsh daily temperatures so the night sky is a critical component to their survival.

Stacy: We have the plant Datura wrightii also known as Sacred Datura. And it is a plant that is known to be a vespertine flowering plant. What that means is that it's reliant on the night for blooming. If you've been in the desert and you've seen the beautiful big white trumpet flowers of the datura plant blooming, they'll bloom in the evenings throughout the night and then also in the morning. They're pollinated by moss and other night critters. It's just a really cool plant to see. If you're out on a moonlight hike, you're going to see the datura blooming, and they're just stunning. There's animals out there that a lot of their behaviors kick in when it’s dark. Frogs and toads, they're mating rituals, require darkness. They'll do their croaking and that's important for them to be able to mate. Artificial light can disrupt these behaviors. And then for humans, we have been intrigued by the skies for as long as you can remember. It's inspired art philosophy, mythology, religions, science. It's such an important resource. The stars help us navigate. You have the North Star, which is about one degree off from our North Pole. Because of that star always in the northern sky, we can use that to help us navigate in a north direction. Specific constellations will come up and they mark the passing of the seasons.

Ian: As Stacey mentioned, there are a lot of forms of life that are dependent on clear and starry skies. However, as technology has progressed throughout time, people have started recognizing change. Within the night sky today, more than ever, the amount of light and air pollution is obstructing the views of our nightscapes. It's important to remember that this doesn't just affect plants and animals, but humans too. We not only rely on it for our sleep patterns, but it is also a critical aspect of many culture’s histories. Losing the night sky means losing their histories and stories.

Stacy: As astronomers were some of the first groups of people to become aware that there was an issue with being able to see the night sky, they started to realize that cities were impacting their ability to look through their telescopes and see stars. You have like observatories, like the Palomar and Wilson and Griffith, that are surrounded by large metropolitan areas and a lot of artificial light, and so they kicked off the alarm bells. “Hey, we need to start doing something different. We're not able to see the stars as well as we should!” Because the park service is so big on preserving and conserving and protecting these natural areas, night skies is an important resource for them to protect. The Park Service has developed a whole team of people devoted to learning about and protecting night skies and educating people about night skies. We have the Natural Sounds and Night Skies division in Colorado and they have scientists that will go throughout the different park units with research grade cameras that stitch together mosaics of skies. They're able to determine the sky brightness. This is the heart of what helped us get our Night Sky designation. This scientific number said this just how dark our sky is. The mission of the Park Service is to educate visitors. We want to teach you about why it's so important to protect these areas, and so there's ways that we can teach you on how to conserve the night sky.

Donovan: And ways to conserve the night sky are a lot easier than you may think. Unlike other challenges, the natural spaces facing light pollution may be one of the easiest problems to tackle in our own homes and communities.

Megan: There are many, many easy adjustments that somebody can make in their own homes that will make a huge improvement to the night sky and the communities and the park. Some of those things are as simple as just closing your blinds when it starts to get dark. Making sure that your outdoor lights are shielded and downward facing and that they're actually not encroaching on your neighbor's property. Other things you can do are, instead of having those bright white bulbs, get those amber bulbs. Use warm colored lights, Get involved in your community and get outside at night. All these little things that you can do can really help bring the community together and really increase the visibility in the night sky.

Ian: A lot of these great tips to reduce light pollution come from some amazing data collected by some pretty cool science. When light pollution first started to cause issues, the naked eye was the main tool for observing it. One could easily spot the difference in the night sky between cities and rural areas. However, over time, technology has evolved and enhanced our abilities to not only observe but collect data about nightscapes.

Stacy: So just like the Night Sky division has a team of people with all the fancy equipment, here at Joshua Tree, we're autonomous in our ability to be able to also collect night sky. We have the same equipment that the Night Sky team has. We've worked very closely with the Night Sky team to collect our data. Since before 2006, we've been collecting night sky data and that data we're hoping over time will show us just how our skies are changing as the Coachella Valley gets more developed. As the high desert communities start to grow, we're going to be able to see what those impacts are and we can work with the lighting ordinance that we've been working with the San Bernard Bernardino County on to try and mitigate some of the impacts of that growth in this area. We have a night sky camera. It's a charge-coupled device that can lower core temperature to negative 20 degrees Celsius. And the purpose of that is to try and mitigate as much of the internal noise that that camera is producing itself with light, so that we can get a more accurate reading of what the incoming light is from the sky. The way the camera works is we mount it on a telescope mount. On this device, it helps to move the telescope. You can go up and down. It's 360 degrees around and we have software that was designed to tell that camera to do a 360-degree stitch of the night sky. First, it'll first point upwards, take a photo directly up above the zenith, and then it rotates around. Horizontal with the ground to take 360-degree photos. Then all those photos are stitched together and we have software that will then analyze the light in that. We have some really incredibly smart scientists that were able to determine what are the natural ambient light conditions. They looked at what are the brightness of all the stars seen in the sky, the Milky Way, the zodiac light, and you can subtract that natural light and that will tell us how much light pollution we have in an area.

Donovan: To summarize what Stacy said, the night Sky cameras collect these long, stretched, panoramic photos of the landscapes and analyze the strength of the light pollution affecting your view in a particular area. These fascinating images help play in important role in identifying problem areas for light pollution. They also inspire educational events such as The Night Sky Festival and promote why dark night skies are essential. We were lucky enough to attend one of the pre-Night Sky Festival lectures where Bob Meadows, a physical scientist who specializes in night skies on the national level of the National Park Service, showcased light pollution images that were taken all over the United States at other National Park units as well as Joshua Tree Specifically.

Bob: I'm here today to kind of talk about the origins of our program. It's very unique. It’s specific to the night sky.

Ian: During the lecture, Bob displayed the images that the night sky camera had taken. Imagine a long rectangle image with a stretched out dome that represents the night sky. Key objects on the horizon give indicators of where this photo was. For example, the Joshua Tree photos had Joshua trees and rocks along the bottom. But now, imagine additional orbs of warmer colors from whites to reds than fading into greens and blues across the horizon. These orbs of color represented light pollution and how it was affecting the darkness of the skies in those areas.

Bob: Start to get a little bigger dome of light and a little more impacts there, moving on as you're getting closer to resources. For the most part, the Zenith is unimpacted. You have a national…

Ian: Bob first showed images from around the United States such as Arches National Park and Great Basin National Park, and then moved into Joshua Tree National Park, starting with Cottonwood Campground.

Bob: So this is at the top. This is Cottonwood Campground. That's in the southeast corner of the park. I don't know how many of you have been there. It's a little more remote from a lot of areas. And as you could tell here, not a lot of light pollution. And what you have here, I pointed out, this again, is the Coachella Valley and looking towards the Los Angeles area. This is looking down towards the Mexico border, kind of El Centro, Mexico, that area pretty is further away. But again, if you have clear skies and clear air, light can travel a great distance. This little knob here, that's actually the city of Las Vegas, back in 2000…

Ian: What Bob was showcasing was almost unbelievably. All the way from Cottonwood Campground on the very south side of the park is light pollution from the city of Las Vegas. A place that is over 200 miles away from Cottonwood campground was still affecting the night sky in the Cottonwood area. The light dome in the photos was significantly smaller than the light dome produced by the Coachella Valley, but was still plainly visible. Remember Cottonwood is known to be one of our darker areas in the park. So, what does this mean for other areas of the park?

Donovan: After seeing these images that Bob was sharing, I realized that I really had no idea just how much light pollution was affecting the park. And yes, our night skies are amazing, but it could be better, especially over the years, things have changed. Bob was an amazing speaker to listen to because he showcased that a great challenge takes a great deal of motivation to help tackle, and it was clear that Bob and his work was not only inspiring us, but everybody else in the room.

Ian: After talking with the phenomenal individuals who helped to conserve our night skies, Donovan and I were feeling pretty stoked to get to the Night Sky Festival and see what loving the night sky is all about. Of course, we reminded each other of the tips and tricks to having a successful time when viewing the night.

Donovan: Right, like avoiding blue lights to allow our eyes to adjust to the darkness. Red lights are always a safe bet. They don't affect the rhodopsin in our eyes, so I usually cover an old headlamp with red cellophane. Works pretty well.

Ian: Oh, and remember, we also have to have patience and give the stars the time they need. This means bringing things like a chair, extra layers, food, water, and anything else you may need to help make for a more comfortable viewing experience for yourself.

Donovan: And don't forget to double check the moon phase and rise time, because remember, the light from the moon is really just the sun's reflection. We want to ensure that we're not trying to stargaze while the sunlight is still present.

Ian: And lastly, it's important to scope out a good star viewing place ahead of time. The desert has a lot of sharp plants and nocturnal wildlife. Personally, I don't want to be in their space just as much as they don't want me in theirs. On top of that, some areas in the park might not accommodate parking after dark.

Donovan: And with that in mind, I'd say we're ready to go to the night sky.

Ian: Upon arriving at the Night Sky Festival, Donovan and I were greeted by dozens of astronomers and night sky enthusiasts with telescopes pointed toward the stars and planets above explaining to festival attendees what exactly they were seeing.

Donovan: I'll be careful. Oh yeah, you can see the rings. That's super cool.

Astronomer: Yes. Clearing up well, I got a clear spot about the time. Yeah, time. I say, oh, that's cool. There goes a cloud. Oh. Oh man.

Donovan: That's super cool. Thank you. Thank you. Through some of these telescopes, we got to see blue, yellow, and red stars. The rings of Saturn and several moons of Jupiter. Some telescopes were even set up with TV screens so large that crowds of people were able to gather around and view the stars from trillions of miles away together.

Ian: While it was hard to pull ourselves away from all the amazing sites visible through the party of telescopes, the Night Sky Festival had an impressive schedule of speakers and live music. So of course, we had to go check it out. In fact, Park, superintendent David Smith was emceeing the event and warming up the crowd

David: Galaxy. It's the creation of human life. It's all coming from above us right now. So being able to connect with that is a wonderful gift. And to be able to see it in places like National Parks is a wonderful gift as well.

Ian: So like any unique ecosystem, the original inhabitants provide a crucial lens into understanding the complexity that is the night. Elizabeth Page from the Native American Land Conservancy took the stage and spoke from the perspective of the people who have been here since time immemorial.

Elizabeth: We have all these stories that tell about these stars because we were the first astronomers, we were the first astrophysicists in this desert. I find that so incredibly beautiful to share that story with you as well as origin stories too. It isn't all Scorpio and Sagittarius. It's also the ram and the snakes and all these beautiful desert creatures that we saw in the stars as well.

Donovan: It was one experience, getting to see the stars and constellations through the astronomer’s telescopes, but getting to just sit beneath them, looking up with the naked eye, getting to hear the stories and perspectives of how the constellations formed, felt irreplaceable to understanding their greater context.

Speaker: We got a lot of stars. We got a lot of constellations up there, and I'm hoping that it gets clear enough that we get to see the Milky Way overhead. So, if these clouds get out of the way a little bit more, what we'll see is over by the teapot. If you go back over to the teapot over here, this is the center of our galaxy.

Ian: You probably noticed in our clips from the festival that a few people mentioned sightings of the rare and elusive desert clouds intermittently passing through the sky that night. It's important to remember that while clouds may come and go and are outside of our control, light pollution, where we live is not. As we wrapped up our time at the Night Sky Festival and headed home, we reflected on what we can do to help ensure that amazing events like this can continue.

Donovan: Right? Because as interpretive rangers, we want to ensure that the park is not only protected, but you get to enjoy it to its fullest. Light pollution is an interesting topic. Because it mostly needs your help at home. It needs to be addressed before you even come to the park. To reiterate those tips on lowering your light pollution impact that Megan mentioned before, you can always make sure that your lights are pointed down and use warm tone bulbs, and better yet, just turn off unnecessary lights that you don't need. It's also a great way to save energy. A flip of a switch can make a world of difference when trying to peer beyond our own.

Stacy: Air pollution is going to take a long time. If we stop emitting all the pollution and just stop doing everything, it's going to take decades for that natural system to balance itself out and rebalance itself. All you have to do for light pollution and noise pollution is turn off the light and stop the noise.

Donovan: Where Two Deserts Meet is an official production of Joshua Tree National Park, co-hosted and written by Donovan Smith and Ian Chadwick. Produced and edited by Donovan Smith. We would like to extend. Special thanks to Stacy Manson, Megan Richie and Bob Meadows for taking the time to talk with us. Sharon Lee Hart for letting us use her artwork titled Split as the Cover Art for Where Two Deserts Meet and Bar Stool for their songs Slow Lane Lover, lanky, Lockley Fells and Feather. For more information about the park, please visit our park website at www.nps.gov/jotr. Happy trails.

In this episode of Where Two Deserts Meet, we hit the trail with Trail Crew Member Dalton Moore and PSAR Coordinator Anna Marini. With their help, we explore what it takes to construct and maintain the trails for you to enjoy and discuss the ins and outs of staying safe while doing it.

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Ian: Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land on which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place. We pay our respects to the people past, present, and emerging who have been here since time in.

Donovan: Hi, I'm Donovan.

Ian: And I'm Ian.

Donovan: And we're both park rangers here at Joshua Tree National Park, where two deserts meet is a podcast where we investigate topics that often require a bit more detail, and sometimes the help of an expert in the field to gain perspective.

Ian: Donovan, you know, if we're going to do an episode about trails in Joshua Tree, we must address that one question, the one that everyone deep down wants to know.

Donovan: Where are the bathrooms in the park?

Ian: Okay. That's very important. But no, what is our favorite hike?

Donovan: Oh, right. Because the ranger's favorite hike is likely secretly the best hike in the park?

Ian: I can totally see how one could imagine that someone who worked here would've come to an eye-opening epiphany of the absolute best trail. But funny enough, it's the opposite. With my years spent here, I've realized every trail has something to offer and the one I'm headed to on any given day is just the one I'm in the mood for. It's as simple as that.

Donovan: And sometimes that mood can depend on what the weather is. A hike that might be my favorite at the time in the winter could be my worst nightmare in the summer.

Ian: Ooh, yeah. Truly, it's just logistically complicated to have a single favorite. No matter how I get asked it. I struggle to find answer.

Donovan: And not to mention that beauty is in the eye of the beholder. I've had a visitor come into the center and tell me that the trail that they hiked was so beautiful that they cried. But at the same time, not even five minutes later, another visitor came in who hiked the same trail and informed me that it was a big waste of time for them. Sometimes we like different things and that's okay,

Ian: And sometimes what I want is just to see everything that is possibly available in a list form, because I must know every possible option before deciding.

Donovan: Well, that's a way to do it, and that's why we have those lists available in the visitor centers and our park website and the NPS official app. Once someone has their trail selected, that's where Ian and I come in at the visitor centers providing tips on how to have a good time on those trails. Usually mentioning that if you want a more secluded hiking experience, starting the trail early is the way to go.

Ian: Speaking of getting up early, I'm reminded of some of the behind the scenes work that goes into making these. It all happens early in the morning with our trails crew. We should talk to trail crew member Dalton Moore.

Donovan: That's funny that you thought of trail crew because when I think of getting up early, I think of the heat safety signs that our preventative search and rescue program puts out. Anna Marini, the coordinator of the preventative search and rescue program would be a great person to talk to also.

Ian: You know what? Let's just talk to them both. Yeah, let's do it.

Dalton: My name is Dalton Moore and I work on the trail crew in Joshua Tree.

Donovan: Dalton is just one of the many trail crew members here at Joshua Tree National Park. They play a critical role in building and maintaining the hundreds of miles of trails in the park. But what does an average workday look like for a trails crew member?

Dalton: An average workday for a trail crew member begins at 6:00 AM, showing up, ready to go with your food, your water, and any comfort items you may need in your backpack. We'll do a morning briefing. We just talk about the day really quickly, and then crews will load up into trucks and drive to their project sites where they could be doing a variety of different things. Usually ends up being dry stone masonry, where we're building trail structures. Crews will then spend the next eight hours or so out in the field where they'll, they'll shape rock, they'll construct structures, they'll drill rock, and they'll eat lunch out in the field. They'll eat snacks out in the field. They'll drink water. They'll do all their normal things, and then they will probably leave the field around three o'clock or so with a goal of getting back to the office by four thirty.

Ian: The projects the trail crew works on can take months, even years of planning and hard physical labor. Depending on where they're working in the park, the crew will utilize the resources around them to create a more natural look to the trail and have less impact. While Joshua Tree might not have giant sequoias or other dense vegetation to help construct trails, we do have a few key resources that play a role in our trail.

Dalton: In Joshua Tree, projects usually consist of building trail structures out of stone. Normally this is stone that is quarried out in the field and they are building steps, water bars, or retaining walls on the trails. In other parks, you could be building these structures out of logs, but since we're in the desert, we don't how many trees but we have a lot of boulder piles. We usually try and query up those boulder piles to make structures about five years before projects. We collect the data on them and that the data consists of what we want to do in these areas or where we see erosion happening or resource damage happening. And we submit the, data of those project site locations to the resources department and they go out in the field and they assess and they usually let us know where is okay to quarry from and where we should hold off.

Ian: Our monzogranite boulders often being known for their durability but when a trail gets thousands of visitors a day, it can see quite a bit of wear and tear trails along Park Boulevard, especially high usage because that's where most of the awesome Joshua Trees and big old boulders can be found within the park. This includes some of the most asked about trails in the park; Barker Dam and Hidden Valley. They can see over hundreds of thousands of visitors a year. This means that the trail crew not only helps build new trails but maintains the existing one. Biggest thing tends to be erosion from rain and wind. But then we also see a lot of social trails that happen since we're in the desert and we don't have defined trail corridors. It can be kind of hard to navigate sometimes. So there's a lot of big webs that get created. We try to lessen those number of webs by keeping people on the trails and creating more obvious paths.

Donovan: Unfortunately, the trails crew aren't the only humans building trails within the park, often done unintentionally, the creation of social trails is a huge concern for park management. Some social trails can be caused by park visitors trying to access points of interest, rock climbing routes, and sometimes by someone simply getting turned around on a trail. Some of these social trail areas that have been around for quite some time have been developed into established paths such as the rock climbing, access routes to Hall of horrors, or the Oyster Bar. And before we go on, know, sadly you will not find an actual oyster bar there, but just some cool rocks that might resemble some oysters. However, social trails can cause more issues than one would think. Social trails often lead to the destruction of delicate ecosystems, trample desert, vegetation, and habitat. They can often become so defined that they resemble the actual trail, often leading people astray. Some of the maintenance that our trails crew does is helping fix the wear and tear from these social trails and natural erosion.

Dalton: Erosion on the trails tends to look like trenching of the trail, which then leads to water channeling down the trail and furthering the erosion. So you get these trails that are really big trenches, essentially, and they're not very pleasant to walk on because it's not a level surface, it's kind of slippery. And so a lot of times what we do is we build stone steps in those trenches that encourages sheet erosion and makes the a durable surface for hikers to walk. We keep trails easy to follow by doing a couple things. I would say the first thing that we do is we prune the vegetation that's growing into the trail. In trails, we call that brushing. We brush out the trails and that makes it so that there's a clear line of sight of where you should walk. The other way that we kind of do that on some of our washer trails or trails that are in large sandy areas is we use signage. And a lot of times what that signage looks like is a trailhead sign at the beginning of the trail so you know where you are and then we use directional arrows. Also that lets you know whether to go straight or make a left or make a right. And, we try to use signage only when necessary or when it's obvious that people are getting lost or at the start of social trails.

Ian: Some of the signs that you're on the right path might not be noticeable at first, but often tune into our common sense of what appears to be the easiest path. As mentioned earlier, most of the trails on Park Boulevard have giant boulders to help signify where to go. But in other areas of the park, such as Pinto Basin Road and the Cottonwood area, vegetation pruning, rock delineation in washes and directional arrows might be your only trail signs. It is extremely common to have several washes cross a trails path. One trail with such an issue is the Lost Palms Oasis trail, a seven and a half mile hike that is really only advisable during the winter months due to the extreme heat of the summer. Now, don't get fooled. Washes are notorious for resembling the trail. Washes are natural areas where large amounts of water moves in a particular direction sometimes across established trails, often clearing vegetation and debris, making the area look like a designated path. Make sure to always stay vigilant and look for those signs that you're actually on the right path.

Donovan: As Dalton mentioned, there are a lot of different signs that they utilize to help let you know when you're on the right path. Of course, installing metal directional arrows can be pretty self-explanatory, but some of those natural signs using rocks and vegetation take a little bit more labor to make possible.

Dalton: It all depends on where you're building material is. If you have a rock next to the trail you would drill into the rock and you drill a series of holes in the rock and then you use wedges and plug to split the rock so you get a flat surface. That is a good stepping surface because a lot of the rocks in Joshua Tree are kind of round and a little more bulbous. We split them to get a nice flat edge, and then you have to dig a hole and you put the rock in it, and you pin the rock in with other rocks. That process from walking up to the rock to when the step is finished can take anywhere from a day to three days depending on the surface that you're kind of digging into to set that rock. One way that we preserve the natural resources of the trail is by not damaging vegetation whenever possible, but also trying to leave some of those rock piles that are close to the trail. Importing rock is one way that we are able to preserve those rock piles and we import rock using either helicopters, which is something that we're going to be getting into within the next year or so. Helicopters, you can put a really long line on the bottom of it and they can act as a crane to pick up a load of rock and then you can set it In the trail. Another way that we transport building materials to project sites is by putting rocks into gas-powered wheelbarrows. Imagine tank tracks beneath a wheelbarrow so that you can drive heavy loads of rock onto trails. That's how we import rock to build trail structures. We may also highline; a high line is basically like a really slow zip line. We query a rock from less visible areas from the trail, and we put that rock on a really slow zip line so that the rock floats over the ground. We don't have to roll it on the ground basically.

Ian: Importantly, deciding how and when to build trails isn't always a zipline process. The parks history and geography play a huge role in planning for new trails.

Dalton: Previous park infrastructure has been a little bit difficult in Joshua Tree since a lot of our trail system has been developed from mapped social trails. Prior to the eighties, at some point, there was no official trails in Joshua Tree. They were all social trails that were then mapped and then added to the park, adopted them into its official trail system. What that means is that a lot of the trails maybe don't follow sustainable grades. They might be a little bit steep in some spots, or they might make sharp turns. Steep trails have increased erosion since the water can run down them really fast so that's been a challenge adapting those social trails and trying to have them meet proper trail standards. I think one of the good things about the historic roads in the park, and by historic, I'm probably talking like 1800s onward. From there, a lot of those roads go to kind of obvious viewpoints that have drawn people in for hundreds of years. They might lead to kind of an obscure peak or kind of a mine, or they go to a certain rock formation. In the desert, you have a really good line of sight, so you can see really far. People have been kind of attracted to the same places for a long time. A lot of the historic roads in the park follow washy areas. Flat areas, and those are fairly sustainable for the most part. They may not be the most pleasant to walk on since they're really sandy, but soil compaction has made it so that vegetation doesn't grow into the trails quite as much. And then a lot of the mines that might be higher up on the hillsides in Joshua Tree, a lot of those roads actually follow pretty decent grades. Super steep. They get you to high points, and the erosion on them is generally okay since they were constructed with road standards, which tend to be a little bit less aggressive than trail standards.

Donovan: An example of a trail that utilizes a historic road is Lost Horse Mine trail, which is a six-and-a-half-mile loop or just four miles if you go to the mine and back on the historic road that leads to the mine. Whereas the Mastodon Loop trail, a three-mile trail that was constructed from older social trails associated with the Cottonwood Mining District. A fun fact about that trail is that no, there wasn't actually mastodon bones found at the site, but that miners at the time thought that the mountain range looked like a mastodon laying down. Areas often appear to be just beautiful landscapes, but are often full of natural and cultural resources. Considering these resources play a critical role when planning and maintaining trails within the park.

Dalton: We plan for natural and cultural resources in the park by gathering data from a trails perspective what we think should be done to the existing trails. We then turn that data over to cultural and natural resources compliance process where we give subject matter experts the data, and then they get back to us on what is feasible or how we can conduct our work in a way that doesn't negatively affect the parks resource. Quarrying rock is definitely something that requires a lot of consideration since that's really the one thing that we do on trails that's irreversible. And whenever we build structures, we use all native rock and we use all natural building material. Usually within the park, occasionally we import rock in from outside the park, but for the most part our work may last a hundred years. If it wanted to be removed, it would be removed and it would. No major effect on the parks resources, but quarrying rock within the park is something that we can't really take back. That's something that gets a lot of consideration. The compliance process for our projects usually takes about a year of the cultural resource department reviewing and really taking into consideration any negative effects that might happen.

Ian: It's amazing all the work the trail crew puts into ensuring the protection of these natural and cultural resources. But the protection of these resources doesn't just stop there. It continues with you, our visitors every day on the trail. Together we can ensure that these areas are preserved unimpaired for future generations to enjoy and learn about while staying safe.

Dalton: Visitors can assist the trail crew by staying on trails. So if you are hiking and you are given the opportunity to hike multiple different routes that all kind of lead to the same area, we just ask that you stay on what appears to be the most developed route and the most obvious path, that makes it easy because with social trails, a lot of times the trails are created by the soil being compacted and once the soil is compacted, you never really get those plants back. If you could just stay on what appears to be the most obvious route, because that is probably what is the real trail.

Ian: So there you have it. Staying on trails is the way to go. Of course, these trail markers only work if they're used correctly.

Donovan: You know, although I work for the National Park Service, I often vacation at other park service sites. A common behavior that I see across the National Park Service is construction of cairns by park visitors. For those of you who are unfamiliar what a cairn is, it's essentially stacked rocks that are commonly used as trail markers. Cairns have a few uses, but can also be destructive when misused.

Dalton: Cairns have a very specific purpose and they do serve a purpose on large, slick rock areas. If there is an obvious path where there is no difficulties wayfinding, you do not need to build a cairn there to let other people know that you were there. Big reason a lot of people like to hike in Joshua Tree is because they like to not see signs of civilization. And a cairn is a direct sign of civilization usually. If you could only build cairns in areas where you think that you truly could get lost, they don't really have a purpose.

Donovan: Cairns also disturbed critical habitat. Joshua Tree National Park is home to thousands of different species of mammals, reptiles, bugs, which all rely on some of the teeniest rock habitat. Moving rocks and stacking them can disturb their homes. Additionally, it can be misleading to potential hikers, thinking it's a directional on the trail. Since Joshua Tree National Park is in a desert, we utilize the resources that we have for trail markers so some of those signifiers might look a little different than other national parks, but keep an eye out for those signs and they can ensure a lesser chance of getting lost.

Dalton: So certain desert specific trail markers that are unique to Joshua Tree, the subtlest of them is pruning the vegetation that's growing into the trail or brushing the trail. We try to guide visitors on the trail without them even knowing it by creating just an obvious path. Probably the next more intensive is we use rocks to line the edges of the trail in certain areas. This is a little bit more of a subtle and a more natural way to outline the area. We ask that visitors to leave those rocks there because if there's rocks inside of the trail, they are there as sort of a way-finding tool. And then probably the next, most intensive way that we mark trails is by using signage. And signage is an effort to keep visitors on trail. Trail brushing is always our first thing. And then if we, if brushing isn't working out and we still are seeing social trails being created, we then go into doing rock delineation. And if rock delineation isn't working, our visitors are moving those rocks, then we would install signage as kind of a slightly more permanent way of wayfinding. But if that still doesn't work, signs can also be removed if need be, and we've done that in the past in areas where we think there needs to be a sign, then we find out there actually doesn't need to be. It is not preferred to have signs because visitors like to hike the trails and not see signs of other humans. Sometimes, we like to respect that by leaving our trails with a natural appearance and signs being made of metal or even if they're made of wood, it still doesn't exactly give the natural appearance.

Ian: Your safety is our priority. We want to make sure you have the best time in the park while hiking the trails, but some of the preparation to having a great time on the trails starts at home with you.

Ian: My advice to visitors would be to show up prepared. So do your homework before you get to the park by doing your homework. Look at the National Park Service website to get official trail information. There's been a huge explosion in the last probably five to ten years of blogs providing information that may not be exactly accurate or other sources of people who have never even been to the park writing about the park. Do your homework before you get here. Find a trail that is a length that is something that is doable or might even be a slight challenge, but where you're not going to overwhelm yourself and to come prepared for that challenge that you're going to be seeing when you're in the park.

Donovan: As Dalton mentioned, there has been a huge uptick of the number of third-party resources providing trail information out there. A day doesn't go by when I'm in the visitor center and someone comes in showing me a list of recommendations from a popular blog to social media videos with someone hiking on a trail and they ask where they can find these places. However, those recommendations aren't always accurate to what they are advertising, or even the places listed in those blogs as the best sunset location might not actually be the best location for that.

Ian: I've actually seen ones where they aren't even showing pictures from the trail they're supposed to be on.

Donovan: Exactly. My best piece of advice that I tell visitors is that if you don't see us advertising a specific trail on our own website, hiking guide, or app, there might be a reason for that. Whether you're going to hike the 36-mile multi-day California Riding and Hiking trail to the casual quarter of a mile trail at Cap Rock. Plan like your life depends on it.

Dalton: I think an important aspect of trail work is that one of our goals is to have our work go unnoticed. I think if we do everything correctly, you don't even notice that you are walking on steps. You don't notice that the trail that you're hiking on has been brushed. You are able to just take in the view and go for a hike for a while if we do our job correctly. Usually everything is pretty smooth and you should be able to just go for a walk.

Ian: Taking a walk through Joshua Tree National Park can be a life-changing experience. Life becomes neat and simple. Time and distances change drastically when you're on foot and the wild world around you that is often taken for granted, becomes familiar and friendly.

Donovan: Of course, getting home safe at the end of the day is an important part of that experience. Anna Marini and her team are dedicated to providing the education to ensure that that happens. Similar to this interview, a lot of her work is done on the trails.

Anna: My name is Anna Marini and I'm the PSAR coordinator here at Joshua Tree National Park. PSAR stands for Preventative Search and Rescue. I'm the coordinator of the program, which is new here, and I manage about 30 volunteers that are out and about in the park.

Donovan: The 30 volunteers that Anna manages cover thousands of miles of trail every year. Even in blustery winds or triple digit temperatures, the PSAR team are out in the park. Anna Marini and her team are truly an extraordinary group of individuals dedicated to ensuring your safety on the trails. When you visit Joshua Tree National Park, you can not only expect to see the team, but also the educational information that they put out as well.

Anna: Volunteer coordination is a large chunk of it, and then also, trying to improve our signage and our communication with park visitors. I have great volunteers and they really don't need much managing at all. It's really just working on the schedule and making sure people are out and about in the park.

Ian: If you see these signs, take a second to read them. These will provide you with the best advice on how to stay safe while recreating in the park, and you can find them all.

Anna: You'll probably see some volunteers out of the trail heads or hiking on some of our popular trails. They're going to be educating visitors on some of the hazards and maybe some of the dangers of Joshua Tree, and they're going to give advice on how to have a good time while you're here on vacation. They also are a wealth of knowledge. You can ask them pretty much any question about the park and they'll do their best to answer. You'll see those volunteers out on the trails. Something else we've worked on is increasing our signage. When you come to a national park, you don't want to be just surrounded by a bunch of signs. What I've worked on is trying to find the right words to put on signs so it's not overwhelming and it gets straight to the point to help you understand what's great to do here in Joshua Tree and how to keep yourself safe on the trails. We've worked on a couple different signs. Right now, I've switched to ‘Winter hiking safety’ Good reminders are: it gets dark a lot quicker here so carrying a headlamp, extra layers, all those types of things. In the summer we tried to explain to people about heat safety, hiking in the heat, what can you do in Joshua Tree when it's so hot. It was a great way to explain to visitors that, yes, you can still recreate here, but let's explain some tips and tricks on how to have fun while you're.

Donovan: Although not every national park you visit has a dedicated PSAR program, the growth of these programs is expanding in popularity. Anna started the program here at Joshua Tree National Park in March of 2021, and we have already seen major improvements to the safety of our visitors. With Joshua Tree National Park visitation still rising from the 3 million that we had in 2021. Programs such as PSAR have kept rescue numbers down.

Anna: Those general winter safety and the heat safety signs that I talked about, those are going to be at your visitor centers and your entrance stations. The information is also listed on the park website. And another version of that kind of sign that we tried this year is I placed two signs at the 49 Palms Oasis Trail, as well as the Lost Palms Oasis Trail. Those give some options on what to do if you weren't planning on doing such a long hike, and it helps explain some of the dangers that we have, and those trails have been the top two trails people just overexert themselves. We really tried to explain how to hike safely and what to do if you weren't prepared.

Ian: And PSAR takes that commitment to education to a new level. PSAR not only helps educate about weather and safety, but also other principles of Leave No trace, and how to be a good steward while in the park.

Anna: PSAR, Preventative Search and Rescue has always been a part of every national park. We naturally talk about preventative measure. To make sure visitors have fun and stay safe while on vacation. It's a natural conversation for our interpreters, for people that are working at the fee booths, things like that. But parks have realized that with an increase in visitation, comes with more people in the park. That could turn into more people getting lost, sick or injured on trail. That happened here in Joshua Tree. We had a huge visitation boom. If you haven't been here, our park is set up in such a way where our visitor centers are primarily on the outside of the park. They are right on the outskirts and once you drive in the park, there's not too many employees inside the park. That’s just the way we're set up. Realizing that, I think we needed to find another way to help educate our visitor. How about we have more people in the park and volunteers are great. They are excited to be out there and enjoying the park just like you guys. And so we're using them to be inside the park and to educate people before they go out on a trail, before they set up their tent, things like that. It was a good way to kind of change the direction, educate people before they leave their cars, that type of thing. But it wasn't necessarily an increase in search and rescues, it was just a per person to person educational contact that we're trying to increase.

Donovan: These volunteers are not only assisting with education, but data collection. This data is used by management for critical decision making.

Anna: A big part of our program is data collection, like you mentioned. We need to figure out what trails are busy, what are the busiest times, how many people we talk to. Our volunteers, after they're done with their patrol, which is what we call the time that they're in the park, they fill out a form and they mention how many dogs they saw, what trail they hiked, how many people they talked to, and something we call preventative actions. Preventative actions maybe they gave somebody a bottle of water that didn't have any water. Maybe they gave them really important directions when they were feeling unsure. They could have even hiked somebody back out to their vehicle if they weren't feeling well or feeling a little confused. We collect those numbers and that's kind of showing what our program is doing. We're not exactly sure if we've lessened search and rescues yet, there's a lot of factors that go in there. The post covid world is a little strange right now, but what we do know is that when we first started PSAR in March of 2021 through October of 2021, the volunteers talked to 14,000 people out on the trails, which is an awesome number. That's 14,000 people that we talked to about seeing tarantulas or different birds hiking on different trails, explaining all the questions that they have because everyone, all park visitors have a ton of questions. Our recent data from last year, October, 2021 to just recently in September of 2022, PSAR talked to 56,000 people. A huge increase. And this last year we did see less search and rescues, especially on those trails I mentioned before, like 49 Palms and Lost Palms. But it'll take a little bit more time to show if it's actually the program or if it’s a combination of things like hopefully people are doing more research before they travel into the parks, things like that.

Donovan: 56,000 people! These conversations are critical for educating about safety. With all of this experience, it's safe to say that these volunteers are very well versed on how to recreate in the park safely. I asked Anna what a visitor could expect from conversations with a volunteer or herself on the trail.

Anna: When I think about trail safety, I always think about being prepared. I teach a personal preparedness class to our employees just to think about what could happen in their day-to-day. And you guys can do that too when you're here on vacation. I'm not asking people to fill their backpacks with a bunch of food and water, but it's really just about being prepared for the day or for the next couple days that you're going to be here. So, of course you want to pack your food and your water for even if it's winter or summer. A lot of people have a hard time snacking on things when it's really hot out. I encourage people to find that special snack that you want to eat when you're not feeling great in the heat. Salty snacks are really great for that. Finding your favorite electrolyte flavor. And then in the winter it's really hard to drink water. It's so cold. It's really difficult. But making sure you're not becoming dehydrated when you're out in the park is always a great tip. There's talk about the 10 essentials. That's anything from making sure you actually pack a little shelter. A shelter could mean a variety of different things, but I like to think about that as extra layers. What's going to keep you warm or cool when you're out hiking? If it's too hot out, actually having proper layers on and different of different types of materials is really helpful. Anytime when I'm out hiking, I'm completely covered with nice cooling material and people probably think I'm really hot out on trail, but it's actually covering my skin and protecting myself from the UV. Something I like to do is spritz myself with a little spray bottle of water or maybe from my water bottle that I have. I call that desert air conditioning. It really helps cool you down and then of course, making sure you have extra layers, hats, and gloves for those wintertime hikes. Like I mentioned before, having a headlamp or an extra light source, don't rely on your phone battery. If it's not fully charged, it's not going to keep the flashlight on. More often than not, I'm talking to people whose phone died and then they have no light. So having a good light source if you hike into the afternoon here in the winter is great. Making sure that you have what you need in case you get stuck out on the trail for an unexpected long period of time. It's possible that somebody in your group could twist an ankle and you need to get wait and get help. Making sure you have a little bit extra food, a little bit extra water for those types of things. That's when extra layers and stuff come in. But really you probably have all these things at home. Just pack your bag before you leave just to make sure you have everything when you're here, and then double check it to be able to run to the store if you don't have everything you need.

Donovan: So it sounds like there's no way to be over prepared, essentially…

Anna: Yeah, definitely. If you look at the back of my car, I have every season back there. I'm ready. Because I want to be comfortable and I want to be fun. Have fun when I'm out hiking, and it's the best way to make sure everyone in your group is having fun and having a good time here is to be prepared and have everything you need.

Ian: Well, there you have it. Follow Anna's tips, and you are not only more likely to have an enjoyable but have fun while doing it. Unfortunately, sometimes things can go wrong while out on a trail. Let's say you're hiking through a sandy area and realize what you thought was the trail has come to an end, or you look up and realize you're surrounded by big boulder piles not able to tell which direction is which. There's no trail signs or even people in sight. Of course, being prepared is the best way to help prevent this, but if it does happen, what next?

Anna: Getting turned around on a trail happens a lot here and it's probably because a lot of our trails are built in such a way where you could easily be hiking in a wash, which is where water flows during monsoonal rains that also look like a trail. It's good to be able to be aware of your surroundings when you're hiking. What I would ask is it's a good idea to download a map on your phone before you leave cell phone service so you're able to reference that when you're out on the trail. You can also purchase a paper map and practice where you're going. Paying attention is always great. If you do get turned around on the trail, I encourage you to stop and take a look around. Don't walk too far away, but it's possible that the trail is just to your right or to your left, or maybe you passed it. A lot of times people can find their way. The next step is to stay. Making sure that you're staying calm. Your whole party is staying calm. Nobody walks off to try to find the trail alone. And then it's always a great chance to check your cell phone, see if you have some service because that way you can maybe find your location on your phone, that type of thing. But we don't have a lot of cell phone service in the park so it's good to be prepared before you go. If you do find yourself turned around, making sure you stay calm, try to find your way, but if you can't, then it's a good time to call for help. You may be able to find a high point where you could get some cell phone service. As long as that feels safe to you. We also have emergency phones throughout the park, but there's also a good chance that you're going to run into another hiker as you're when in the park. Pay attention to listen to see if you can hear any other people's voices. They can direct you back to the trail, that type of thing. Otherwise, it's always good to move as a group to make sure everyone stays together and you don't leave anyone behind. Then you can look for some footprints to find your way out.

Donovan: Heat related illnesses make up a majority of the rescues here in the summertime. Trail lengths that might be easily obtainable in someone's hometown with a different UV intensity might be a different story here in Joshua Tree National Park under the hot desert sun. What if you're not lost, but that three mile hike you decided to take in the middle of summer starts to catch up to you?

Anna: You can start to self-cool yourself if you're on trail and you're starting to overheat a little bit. People think we don't have a lot of shade here, but our Joshua trees and the boulders and a lot of our other bigger bushes do provide a good amount of shade. Most of the time your body just needs to cool down. Maybe that's using a bandana that you have or a scarf and pouring some water on it and wrapping that around yourself is always a great idea. Continue to drink that water, eat some snacks. Use those electrolytes that I mentioned, but try to cool yourself as much as you can If you have a jacket or a tarp in your backpack it's a good way to make a little shade structure so you can cool down, but normally your body just needs a break. Once you're starting to feel sick and hot weather, it's your body saying, ‘Hey, we did too much. You don't want to continue that activity!’ It's just always great to start to cool down and find a spot to hang out for a bit.

Donovan: Our bodies are great communicators. They always try to let us know when they need something, so make sure to listen to them. Heat related illnesses can present slightly different for each person, but once you start to notice that change, it's important to take it seriously. Great job. Hiking and talking at the same time.

Ian: Trying to plan and prepare for a fun, safe, and successful day of hiking in Joshua Tree National Park can feel like a lot, but we want to remind you that us rangers are still human and understand that even the best laid plans can run into hitches. I personally give the advice to get into the park nice and early to start your hike and avoid the crowds, but still catch myself on my own vacations, slow to get moving and make it to the trail heads early. Does this mean my trip is ruined? Absolutely not, because I've learned that just as important as it is to plan ahead, it is important to be flexible.

Donovan: There's a chance that the trail you are planning for has no parking available. We can guarantee that there are other amazing options that will blow you away.

Ian: Or being flexible and recognizing that your body might be ready to tap out for the day and that's okay.

Donovan: Or you checked the weather ahead of time, but the winds have picked up and are unfriendly to hike in. You can still see just as much driving through the park as you can hiking.

Ian: No matter what corner of Joshua Tree National Park you end up in or how you get there, remember, it's your experience and what you make of it.

Donovan: Where Two Deserts meet is an official production of Joshua Tree National Park, co-hosted and written by Donovan Smith and Ian Chadwick, produced and edited by Donovan Smith. We would like to extend special things to Dalton Moore and Anna Marini for taking their time to talk with us. Sharon Lee Hart for letting us use her artwork titled Split as the Cover Art for Where Two Deserts Meet and Bar Stool for their Slow Lane Lover, Lanky, Lockley Fells, and Feathers Soft. For more information about the park and our hiking trails, please visit our park website at www.nps.gov/jotr. Happy trails.

In this episode of Where Two Deserts Meet, we sit down with Dr. Cameron Barrows of the University of California – Riverside. With his assistance, we break down what exactly it means for two deserts to meet in Joshua Tree National Park, what that truly looks like out on the landscape, and how it is changing before our eyes.

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TRANSCRIPT:

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Donovan:  Where Two Deserts Meet is an official podcast of Joshua Tree National Park. Joshua Tree National Park acknowledges the Serrano, Cahuilla, Mojave, and Chemehuevi people as the original stewards of the land in which the park now sits. We are grateful to have the opportunity to work with the indigenous people in this place, and we pay our respects to the people past, present, and emerging who have been here since time in Memorial.

Donovan: Hi, and welcome to Where Two Deserts Meet, a Joshua Tree National Park Official podcasts. My name is Donovan

Ian: and I'm Ian.

Donovan: And we're both park rangers here at Joshua Tree National Park, Where Two Deserts Meet is a podcast where we investigate topics that often require a bit more detail, and sometimes the help of an expert in the field to gain perspective.

Ian: You know, I had a visitor recently asked me about where the line between the two deserts is and Joshua Tree. They were looking for a spot where they could pull off that stand in both places at once kind of thing. But I realized I don't really have a solid answer for them. I usually refer to our park brochure where we have the transition zone labeled or just tell them to look for certain plants that grow in each desert.

Donovan: Yeah, that's still a great resource, but we've actually come to understand that it's a lot more complicated. At almost 800,000 acres, slightly bigger than the state of Rhode Island, Joshua Tree National Park is a large, vast open landscape of desert plants, animals, vibrant night skies, and fluctuating climate conditions. Joshua Tree National Park visitation has also skyrocketed to over 3 million visitors in the past few years, pulling in among the top 10 most visited national parks in the country. If you look at a general summary of Joshua Tree National Park in any sort of guide or travel blog, the first few lines usually start with Joshua Tree National Park, a place where two deserts meet, referring to the Mojave and the Colorado Deserts and the transition zone between them.

Ian: But wait, what even is a transition zone? If we're going to use that terminology, we should probably define it, right?

Donovan: Oh yeah, of course. But it's fairly hard to define. I have always been told that there's usually some good indicator plants that define where those boundary lines occur within the two deserts.

Ian: All right, I got this. If I recall correctly, the well-recognized Colorado Desert plants are the Paloverde and the Ironwood, which are often seen down near the south entrance of the park. Whereas in the Mojave, you would look for the famous Joshua Trees, which are usually seen on the north side and especially along Park Boulevard.

Donovan: Working in the visitor centers, I have actually seen a lot of confusion with this firsthand, especially visitors who come in through the south entrance of the park expecting to see a Joshua tree, not realizing that they're actually almost an hour south of the nearest Joshua tree.

Ian: Yep. That's definitely something a lot of us, park rangers at Joshua Tree, have experienced.

Donovan: But I personally think that driving through the transition zone between the Mojave and the Colorado Desert is a huge part of what actually makes Joshua Tree National Park so special. You drive around the corner from any direction, and suddenly new plant life and geological structures appear. For the visitors who are asking about this transition line, how do you usually describe to them where to go?

Ian: Well, if I'm at one of the north side visitor centers, I usually tell them to start driving down towards the south end of the park, and they will visibly start to see a shift as they get further and further down. But there isn't really a definite line to look for, mostly because the line is changing.

Donovan: Wait, how was it changing?

Ian: Well, if you came to the park a few centuries ago, the transition zone might have looked fairly different. It's changing because of more than just one factor, but I know just the expert to talk to about this, Dr. Cameron Barrows of the University of California Riverside's Center for Conservation Biology.

Ian: So, we've been driving about an hour now, and we've found ourselves on this beautiful campus. Where are we right now?

Donovan: We're actually at the University of California Riverside, but they're extension campus over here in Palm Desert. What's kind of funny though, is when you're driving on the freeway, you wouldn't really know that you're hitting Palm Desert because it's labeled as other desert cities.

Ian: Honestly, that's probably one of my favorite signs ever in the history of signs. It really does capture how people feel about the desert. There are a few big cities that everyone knows, like Palm Springs and Joshua Tree, but the other ones are just “other”…“other desert cities.”

Cameron: Hello. My name is Dr. Cameron Barrows and I'm an emeritus professor or researcher with University of California Riverside, just recently retired. I've been working in the desert for about 35 years or so. Primarily developing conservation programs for endangered and rare species, but more recently focused on how animals and plants are interacting with their environment and how that environment has been affected by humans and more specifically, climate change.

Ian: So, a project that I'm interested in hearing a little more about is one that is titled Managing Species in Transition Zones in the Face of Climate Change in Joshua Tree National Park. Can you tell us a little bit more about this and what spawned this project?

Cameron: Sure. Well, what spawned the project was, probably ten, twelve years ago, there was a research publication that indicated that Joshua Trees would be eliminated from the California landscape as a result of climate change. I somewhat jokingly went to the National Park Service and said, “before you change your name to Creosote Bush National Park, maybe we should look at this in a little bit more detail and focus the scale on the park itself.” The park loved the idea, but they wanted us to look at more than just Joshua Trees, but at the entire ecosystem. As we all know, Joshua Tree straddles both the Mojave and the Colorado Deserts. That's the transition zone between the lower hotter dryer Colorado Desert, and the somewhat cooler, somewhat moister Mojave Desert. What we were looking for is a couple of dozen species to see how each of those might respond to climate change over time. But it's affecting us right here where we live, and it's affecting us now. It's not something in the future, it's a current issue.

Donovan: Okay. So just to take us back, we've clearly established that there are two deserts within the park, the Colorado and the Mojave. But how exactly do you know which desert you're standing in while you're inside the park and where exactly should you look for that transition zone? Luckily, Dr. Barrows was able to provide us some key signs to look for.

Cameron: Well, the Colorado Desert has its own set of species, but there's some overlap. One of the primary species that goes both ways is the creosote bush, and turns out from our analyses, the creosote bush is probably one of the most resilient species to climate change. They don't seem to care all that much. They don't look all that great by the end of summer, but as soon as it rains, they pop right back again. So, that's good news. With regard to that, the Colorado Desert, the lower desert, some of the characteristic species are palm oases. So, the palm Oases within the park are part of the Colorado Desert. Another species that's characteristic of both the Colorado Desert and the Sonoran Desert are ocotillos. As you are transitioning into the Mojave Desert, you start picking up more yuccas, and especially the Joshua Trees. Ultimately at the higher elevations, you're picking up pinions and junipers as well.

Donovan: Plants are great indicators to use when identifying what desert you might be standing in. Now, of course, we've already started to establish that these transition zones might not be so clean-cut. Oases are typically found in the Colorado Desert, but can also be found in the lower elevations around the city of Twentynine Palms, which traditionally identifies as the Mojave Desert. This is a great reminder on how nature doesn't always identify with the lines that we draw on maps.

Cameron: Well, one of the quotes that I sometimes use is basically that the only thing constant about our earth is change and it's been changing for hundreds of millions and billions of years. On a geologic time scale, if you think about, when the first Native Americans, the indigenous people came to this region, which is anything from 15,000 to 20,000 years ago, somewhere in that range, it was a completely different place. It was much, much wetter, and much, much cooler during that period. There were camels, there were horses, there were… native horses, not introduced horses. There were mastodons and mammoths and giant ground sloths and a very, very different landscape than we see today. Junipers and the pines would've been more extensive. More oaks. Species would've made living in this region much easier for those first inhabitants that came here, but that was at the end of the last glacial, maximum of the Pleistocene. So, whether or not we're still in the Pleistocene or not, we'll have to wait another 20 or 30,000 years to see whether or not we shift back into another glacial period. But currently we're in an interglacial period, which is a drier, warmer period, and so as a result of that dramatic climate change, of course we don't have wild camels. We don't have native wild horses, we don't have mastodons, we don't have any of those mega type species that used to occur here; and what has replaced them with are things that have moved up from the south, from the tropics. Cactus, which they are an iconic species of deserts plants, actually their origin is in the tropics. If you go to Costa Rica or if you go to the islands in the Caribbean, cactus grew all over the place. Cactus are very happy in hot places, but they're also not too unhappy about being in a wet place. Except for, and this is the caveat, is that where they primarily occur in the tropics is as epiphytes at the tops of trees. So, capturing a fair amount of water as it's falling through the trees, but there's no soil in the trees, so their roots dry out really quickly afterwards. So that adaptation of dealing with both wet and dry, adapted them to living in a desert.

Ian: Considering what we know about how desert plants have adapted to these extremely harsh and various environments, we wanted to know how those landscapes are changing in the present. So, we asked Dr. Barrows, what are some factors as to why we are seeing such drastic shifts in desert plants as compared to the past.

Cameron: There's two real driving factors: climate change being one of them and the other one really is invasive species. Joshua Trees are in an interesting position in that they are in a pattern of air movement that comes from Los Angeles, and that Los Angeles air continues up to this point. This is one of the potentially good things about people adapting to climate change, if we reduced our impact on our use of cars in trucks and trains and things that burn fossil fuels. That air pattern that's coming from Los Angeles will be cleaner. Right now, it's really dirty. It's filled with nitric oxides of various chemical formulas and those nitrous oxides fall into Joshua Tree as well as much of the Mojave Desert. When they fall, if you were a farmer, you're thinking, how do I increase my crop yields? Well, let's add nitrogen to the soil. Those nitrous oxides are adding nitrogen to the soil. What's wrong is that Joshua Trees don't care about it and neither do bushes or junipers or pinions. They don't respond to that extra nitrogen at all, but what does respond to nitrogen is invasive species. Invasive grasses, invasive mustards, things like that, have moved in. On its face value, it’s really bad, but what makes it much worse is that those species carry fire. Fire has become, in recent decades, a component of the Mojave Desert, which it never used to. There was never enough fuel to allow a fire to move from one Joshua tree in the next Joshua tree or one creosote bush to the next creosote bush. Now those spaces between the trees and shrubs are filled with invasive grasses or invasive mustards, various types, and as a result of that, fires carry across the desert. Some of the listeners might be aware that Cima Dome burned just this past summer, and I think it was a lightning strike, which is a natural event, but it would've hit only one or two Joshua trees and that would've been the end of it, but because of the invasive grasses and other plants, the fire moved in and burned thousands, and thousands of acres, killing most Joshua trees in its path.

Donovan: The Cima dome fire that Dr. Barrows is referring to was a fire that burned about 44 thousand acres of Joshua trees in and around the Mojave National Preserve. Around August of 2020, over one million Joshua trees were burned in this fire. I got a chance to follow up with Drew, a Mojave National Preserve botanist, and he said that the dome fire was started by multiple dry lightning strikes. It was the same storm system that started much of the record breaking wildfires that we saw during 2020. Invasive grasses were just one factor that led to the size of this fire. Also, it was during an extended drought period and a heat wave this same week that Death Valley hit 130 degrees fahrenheit for the first time. Winds were strong and erratic contributing to unpredictable fire behavior. The science is clear that invasive grasses can be an issue when it comes to wildfires, but luckily, Dr. Barrow's research can assist with this issue.

Cameron: What my science is supposed to do is inform management and help them make decisions. Most of our land managers, whether it's the Park Service or the Bureau of Land Management or local nonprofits, land management is an expensive, under undertaking, and there's not a lot of extra money for that. The science that we do is try to inform the managers as to what the risk is if you don't do anything about this invasive species. And so, what is the impact of that species on the environment? Is it indirect competition with native species? In some cases, that's true. Is it changing the ecosystem so that the native species don't reproduce or they can't exist there anymore? Or is it facilitating fire? Or is it doing none of the above and, and just ignore it because the effort to get rid of it would not be worth the benefit you get from it. Deserts are defined by being dry and for the most part, warm or pretty hot. There are some deserts that are cold deserts, but they are still dry. The main factor that defines a desert is how much rainfall it gets. Temperature impacts that because the warmer it gets, the less of that rainfall actually gets to the plants. It evaporates away. In the Colorado Desert, which is a warmer desert, when we do get rainfall, the rain, a certain percentage of that evaporates and never gets to the plants, never gets to the animals. As it gets warmer, that percentage gets less and less and less. And the same is true for the Mojave Desert, so what we're finding in this transition is that the areas of what we would call the Mojave Desert, they have Mojave Desert plants like Joshua trees that are in that. Transition zones right near the Colorado desert, Joshua trees are no longer reproducing. You can drive through there, and if you're not looking carefully, you'll say, “well, there's a bunch of Joshua trees, what's the problem?” But if you do look a little carefully, you'll see that they're all the same age. They're all adult plants. There's no reproduction happening that's replacing those that naturally die from old age. And so what we're seeing as a result of climate change is in that transition zone with respect. Mojave Desert plants, those that are characteristic of the Mojave Desert are either dying, but more importantly, they're not reproducing in that transition zone or near that transition zone. So even as a visitor would drive by and say, “I'm seeing lots of Joshua trees, what's the problem?” You have to look more carefully and ask yourself if you’re seeing any little Joshua trees? Are you seeing the ones that are going to replace those big ones so that in fifty to a hundred years when our children or our grandchildren visit the park, that they'll have a similar experience? What is happening already is that it's much hotter and it's much drier, and that's already the been the case. I've been looking at drought cycles over the past roughly a hundred years, and in the first 75 years there was major droughts that were really debilitating to the plants and animals here. In the last 25 years, we've had three, and this year looks like it might be number four. If you extrapolate that out for the next a hundred years, then we are on the path of seeing twenty to thirty or more severe droughts affecting the plants. Even creosotes, which I said earlier are at this point seemingly resilient to the effects of climate change. They'll start to not be able to reproduce and they'll eventually not be on the landscape. The Joshua Trees are, this is happening quite quickly. It's also happening quickly with the Ocotillo, and we're seeing that across the board that many, many of the species that we consider iconic of desert habitats are able to handle the amount of heat and especially the amount of drying. When we talk about climate changes, there's another euphemism called global warming, but it's much more than that. It's really, at least in our deserts, global drying. If you lived on the east coast of the North America or in the Southeast, it's a very different situation. Climate change is going to make it warmer. Yes. But it's also going to make it much wetter. And so the flooding that we've seen in the east coast in the last four or five, ten years…that's climate change. And all those people that are pushed out of their houses…that's climate Change.

Ian: When talking about climate change, many have heard of what the research indicates for the future and it can be, frankly, overwhelming. However, change is possible, but we must start now. It's important to remember that people like Dr. Barrows aren't just focused on what could happen, but also what we can do to shift the trajectory.

Cameron: In the short term, the trajectory is very clear. It's getting much warmer and much drier, and that's impacting a lot of species. But what we're finding for many of them, maybe not all of them, for many species, there are places on the landscape that are going to be, at least for the shorter term, maybe the longer term, resilient to those effects. It could be north facing slopes, it could be a little bit higher elevation. What we refer to those as climate refugia, that these species will be able to sustain populations in those little patches. We've identified, for instance, within Joshua Tree National Park that if we get serious about climate change right now and start shifting out of a carbon-based economy and, and we get real serious about it, we'll still lose close to 75% of the Joshua trees. That's the current trajectory. The 25 or 30% that don't get lost are in this area that I call a climate refugia. They're resilient to a large extent, but not if we just choose to do nothing. If we say this is something we're going to let our great-great-grandchildren worry about, we're not going to deal with it ourselves or even our own children to worry about. We're not going to deal with it. If that's the path we take, then all the Joshua trees in the park are gone. It doesn't mean that they're gone extinct everywhere, but within the park, they're gone.

Donovan: In Dr. Barrow's research, he mapped out in detail ways in which the Joshua trees are shifting through the park, but he also noticed that there are certain areas in the park that Joshua trees are able to find a sort of refuge, often providing the necessary resources, plants and animals need in order to survive these areas, also known as Refugia can teach us a lot about how plants and animals are adapting to changes and potentially ways in which we can adapt ourselves.

Cameron: Yeah, I think the refugia are, the hope that we have. It’s one of the reasons that I started focusing on refugia as part of my research is that from the standpoint of a park manager or a land manager or somebody who cares about the environment. Climate change just looks overwhelming in terms of the loss of animals and plants, the loss of biodiversity, and because the sources of the change carbon-based economies are so pervasive the world. It's easy for a land manager to say, “well, I can't do anything about this. And these animals and plants, not only I'm being paid to take care of them, but personally I'm passionate about taking care of these animals and plants and I can't do anything about it.” I looked at that and said, “well, maybe there is something you can do about it.” If we do identify these refugia and we protect those refugia as much as we possibly can, which again means controlling invasive species so fire doesn't become an issue or invasive species that might be competing with the native plants. That gives those refugia more time to exist while the rest of us humans get our acts together and start really being serious about changing the way we treat our earth. What we think is likely to happen and we're seeing this already is that there is this boundary. It's a broad boundary. It's not a lot of time you see a line on the map and you think if you stand one foot on each side of the line, one of your feet will be in the Colorado Desert and your other foot's going to be in the Mojave Desert. That's not the case. It's a broad, broad zone, and the maps don't let you know that that's the case. You see the sharp lining. You think, “well, here I am,” but it's like you're moving from one county to the next county, and that's not the way it is. But if you think about it as the Colorado Desert plants, if climate change doesn't overwhelm altogether, they will start shifting into what is now the Mojave Desert. The Mojave Desert will look more like what the Colorado Desert looks like, and the Mojave Desert will have to shift to higher elevations. So within the park, highest elevation is about 6,000 feet, but most of the high elevations within the park are sort of the 4,000 to 5,000 zone. In that zone, the higher levels, like the 5,000 feet up to 6,000 feet, those are where those refugia you could be, especially if they're on north facing slopes and especially if they're at the western edge of the park because the western edge of the park probably gets double the rainfall that the eastern side of the park gets and a little bit cooler. That's where the refugia is going. They will be able to sustain populations at least for the next few decades, and maybe longer, hopefully. But then if you look at it broadly, you think, “well, then the Mojave Desert is going to be shifting up.” Mountains and so up towards Big Bear in the San Bernard Bernardino Mountains or on the other end of the spectrum, up towards Mount Jacinto. There's a lot of room to move when you look at it from that broader landscape, but when you look at Joshua Tree itself, 6,000 feet is the limit. There's no more habitat beyond 6,000 feet. We already are seeing species that have hit that limit and we won't see them anymore. There's a very few manzanita left. There's a horn lizard called the Blaine Fields Horn lizard, and right now they're just at that top, top level. A little bit more warming, a little bit more drying and they're popped off the top of the park, which again, doesn't mean they're extinct yet. It means that the only populations that are going to be able to sustain themselves as the ones that can move up the San Bernardino Mountains or up the Santa Santo or Santa Rosa mountains.

Donovan: Listening to Dr. Barrows, it's clear that things are changing. Plants and animals are having to adapt and learn at faster paces in order to survive. Luckily, wildlife and plants inside Joshua Tree National Park, are no strangers when it comes to adapting and overcoming. But it doesn't mean that there won't be effects from this long-term struggle. What's important is that there is still time to change things.

Cameron: This is a very good question and it's a very complex answer. One of the classes I teach is called Climate Stewards, and it’s the goal of the class to teach people to both understand climate change, but also feel empowered to do something about it. And that, I think, is the crux of things that people don't feel empowered to do anything about it. As a scientist, if another scientist or a knowledgeable person came and said, “this is happening and it's really bad, and here's the data that shows it”, that's what I want to see. I want to be able to look at that data and say, “yeah, could anything else explain that? No, it doesn't look like it, or it does”, and then I can either get on board or not get on board. What psychologists have found is that the science is crystal clear, and yet people are still not getting on board, so more doesn't actually help. And so what we need to do and what as park interpreters you need to do is to show them not only how it's going to infect them in terms of their experience in the park but that the park is this incredibly important national treasure, and it'll be changed in many of the species that we thought were protected. What the psychologist tell us anyway is that you really have to make it clear that it's not just that a Joshua tree is not going to be able to live where it used to live. This is something that affects every single living thing on earth, including us.

Ian: What we're trying to capture, right? We're trying to capture the diversity of both.

Donovan: With new insight into the ways in which the transition zone is changing, Ian and I went to the Ocotillo patch just off of Pinto Basin to see the effects of these changes. Just shortly after driving south passing White Tank campground, we noticed the Joshua trees were becoming smaller and less of abundant with not a single Joshua tree in sight. Once we passed Stirrup Tank Road, experiencing in person what Dr. Barrows was talking about, made everything feel very real. It made us think about how with three million visitors coming to the park each year, sometimes the park can feel a bit overwhelming, but it actually gave us hope. It gave us hope that if each of those three million visitors who come to Joshua Tree National Park connect with it and find out what it is that makes this place so special, then together we'd be able to make a difference. Of course, we can make individual choices in our own personal lives to help lower our impacts using less electricity, conserving water, reduced gas consumption. Throughout history, all great change not only came from individual action, but a collective movement. Increasing wildfires, drought, extreme weather, to see a decrease in the effects of climate change, we must be the change that we want to see.

Donovan: Where Two Deserts Meet is a production of Joshua Tree National Park, co-hosted and written by Donovan Smith and Ian Chadwick, produced and edited by Donovan Smith. We would like to extend special things to Dr. Cameron Barrows for talking with us, Sharon Lee Hart for letting us use her art piece titled Split as the Cover of Where Two Deserts Meet and Bar Stool for letting us use their songs, Slow lane, Lanky, Lockley Fells, and Feather Soft as the music for Where Two Deserts Meet. For more information, please visit our park website at www.nps.gov/jotr. Happy trails.