American bison bulls (Bison bison) in Blacktail Deer Plateau at Yellowstone National Park, Wyoming, USA - Fotografía de stock

The American bison (Bison bison), also commonly known as the American buffalo or simply buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds. They became nearly extinct by a combination of commercial hunting and slaughter in the 19th century and introduction of bovine diseases from domestic cattle, and have made a recent resurgence largely restricted to a few national parks and reserves. The American bison is the national mammal of the United States.