Grasslands National Park is a place of superlatives; abundant wildlife, subtle, yet breathtaking landscapes and expansive, prairie vistas. Unfortunately, after a century of human exploitation, the complex mixed-grass prairie ecosystem is one of the most endangered environments in North America. The park's research team is attempting to restore it to its former glory. Completely absent from the park a decade ago, the Swift Fox is being slowly and successfully re-introduced. Grasslands' signature species is the fascinating prairie dog, who have built residential 'colonies' throughout the park. Ranching is both a livelihood and a way of life for the ranches adjoining the park, and we join them on a cattle drive.