Yellowstone Bison Are Built for Winter Survival

With a dense coat, a powerful mass of muscle and a large head ideally suited for clearing away snow and locating buried grass, bison are built for frigid conditions in Yellowstone. If it wasn’t for a hidden herd in the deepest reaches of this National Park, bison would have been wiped out in the late 1800s. Today, thousands of them thrive. (03:55)