As winter approaches, the slow season is setting in across the National Park System, which makes it a good time to take measure of some issues that are confronting both the parks and the National Park Service. We’ve invited Kristen Brengel, senior vice president of government affairs for the National Parks Conservation Association, and Mike Murray, chair of the Coalition to Protect America’s National Parks to discuss air tour planning in the park system, progress made under the Great American Outdoors Act, and visitation issues.