America's National Parks at 100

The National Park Service has been active for over a century preserving and protecting over 400 units across America, from the wild and natural to the man-made and historic. Take a tour through iconic Yellowstone and the Grand Canyon and discover smaller, hidden treasures throughout the country as we explore the agencys evolution over the last century. Through rarely seen footage and stunning aerial views, we celebrate the sites and stories of the national landmarks that reflect our countrys past, present, and future.

Yellowstone National Park is home to a vast array of landscapes and a huge diversity of animals, united in a fascinating ecosystem, one that is currently in severe trouble. The area once contained over 19,000 elk, but its numbers have plummeted by 80% in the last two decades. The mysterious decline has sparked many questions, and researchers are in a race to provide answers. Join them as they investigate a series of theories and suspects, from wolves to bears to trees to trout, in an attempt to solve this alarming puzzle.