Dubbed "America's best idea" by Wallace Stegner, national parks encompass 84 million acres of diverse landscape from the Everglades to glaciers to redwood forests. 

But in the 21st century, America's national parks face unique challenges. Are they being loved to death? Can they sustain their fragile ecosystems?

National Parks - Troubled Edens examines the future of our national parks from Grand Canyon to Yellowstone and includes "Utah's Crown Jewels" - Zion, Bryce, Arches, Canyonlands, and Capitol Reef.