We're closing out the year with a look back at some of the top stories around the National Park System, and involving the National Park Service. We opened this look back a week ago, with Kristen Brengel from the National Parks Conservation Association, and Mike Murray from the Coalition to Protect America's National Parks, discussing issues involving the National Park Service, and outside impacts affecting the National Park System.

Today, in the second half of this discussion, we're focusing on natural resource issues in the parks.