Many of us like to take a walk in our favorite national park, whether it's a short stroll down one of the boardwalks at Yellowstone National Park, the hike to the top of Old Rag at Shenandoah National Park, or up the Mist Trail at Yosemite National Park, we like to get out and experience parks up close.

As you might imagine, there are walks in the National Park System, and then there are walks. Kevin Fedarko and his photographic sidekick Pete McBride took one of those "other" hikes in Grand Canyon National Park. And it didn't initially go as planned. While Fedarko raised some serious blisters on his feet that required duct tape to protect, McBride almost needed a medical evacuation from the backcountry.

Still, the hike - or rather hikes - generated a compelling book from Fedarko titled, appropriately enough, "A Walk in the Park: The True Story of a Spectacular Misadventure in the Grand Canyon".