A symbol of the wild west, the American bison is the heaviest land mammal in North America. Also called the American buffalo, the bison has a large head with relatively small, curving horns. It has a shaggy coat of brown hair on its shoulders and legs, while its body has shorter, finer hair. Bison are 5 to 6 feet long and weigh 900 to 2,200 pounds.
Males are larger than females on average.
Historically, bison numbered an estimated 20 million to 30 million. Today, approximately 250,000 remain in the United States. Of those only 16,000 roam in the wild. Yellowstone National Park has the only population of free-roaming bison. Bison typically live between 12 to 15 years.