The American bison is the heaviest land mammal in North America.
Historically, bison numbered an estimated 30 million to 60 million. Today, approximately 200,000 remain in the United States. Of those only 16,000 roam in the wild. Yellowstone National Park has the only population of truly free-roaming bison.
Shooting bison for their hides was a favorite frontier sport in the 19th century. Hunters practically eliminated the bison by 1890. In 1893, the first efforts were made to protect the animals. Today, the bison of Yellowstone National Park face the threat of slaughter when they exit the park and enter the state of Montana. The Montana Department of Livestock fears the contamination of cattle by bison carrying the disease brucellosis, although there are no known cases of brucellosis passed by bison to domestic cattle in the wild.
Bison typically live between 12 to 15 years.
A symbol of the wild west, the bison can still be found on the Great Plains, in prairies, and forests in parts of Canada and the western United States. Also called the American buffalo, bison typically reach 5 to 6½ feet in length and weigh 900 to 2,200 pounds.
Bison eat grasses and sedges, moving continuously as they eat so that they do not overgraze an area. They live in herds of 20 to 50 animals. The females, or cows, lead family groups. Bulls (males) remain either solitary or in small groups for most of the year. Bison can reach speeds of up to 30 mph.
Bison are found in Theodore Roosevelt National Park, ND; Badlands National Park, SD; Wind Cave National Park, SD; Grand Teton National Park, WY; and Yellowstone, WY.