Bull bison

Bull bison crossing Yellowstone River. Answer to the frequently asked NPS questions: “Yellowstone is the only place in the United States where bison have lived continuously since prehistoric times. A number of Native American tribes especially revere Yellowstone’s bison as pure descendants of the vast herds that once roamed the grasslands of the United States. The largest bison population in the country on public land resides in Yellowstone. It is one of the few herds free of cattle genes.” Photo by Jim Peaco / Yellowstone National Park Service