Explore a surprisingly wild and little-known part of America's heartland, and witness the efforts to restore it. In northern Montana is a massive wildlife sanctuary on track to become one of the largest, protected ecosystems in the United States: the American Prairie Reserve. Here, scientists and ranchers are working in partnership to restore these grasslands to their natural state. To do that, they must bring back the animals, starting with the keystone species: Bison. Enter America's heartland and witness surprising landscapes and never-before-filmed animal behavior,