This group of bison on Highway 7, north of Fort Liard, refused to move off the road for traffic.. -- Kerry Kraft photo

The American Bison is a bovine mammal, also commonly known as the American Buffalo something of a misnomer as it is only distantly related to either of the two "true buffaloes": the Water Buffalo and the African Buffalo.

The bison originally inhabited the Great Plains of the United States and Canada in massive herds, ranging from the Great Slave Lake in Canada's far north to Mexico in the south, and from eastern Oregon almost to the Atlantic Ocean, taking its subspecies into account. Its two subspecies are the Plains Bison (Bison bison bison), distinguished by its smaller size and more rounded hump, and the Wood Bison (Bison bison athabascae), distinguished by its larger size and taller square hump.

Wood Bison are one of the largest species of cattle in the world, surpassed in size only by the massive Asian Gaur and Wild Asiatic Water Buffalo, both of which are found mainly in India and Southeast Asia.

Bison have a shaggy, dark brown winter coat, and a lighter weight, lighter brown summer coat. Bison can reach up to 2 meters (6½ ft) tall, 3 metres (10 ft) long and weigh 900 to 2,000 lbs (400 to 900 kg). The biggest specimens on record have weighed as much as 1140 kg (2,500 lb). The heads and forequarters are massive, and both sexes have short, curved horns, which they use in fighting for status within the herd and for defense. Bison mate in August and September; a single reddish-brown calf is born the following spring, and it nurses for a year. Bison are mature at three years of age, and have a life expectancy of approximately 15 years in the wild and up to 25 years in captivity.

One very rare condition is the white buffalo, where the calf turns entirely white. It is not to be confused with albino, since white bison still possess pigment in the skin, hair, and eyes. White bison are considered sacred by many Native Americans.

Due to its size and the protection afforded by living in a herd, the bison have few enemies besides humans. Grizzly bears and wolves may attempt to attack young calves or subadults, but only in the dead of winter when the herd cannot expend the energy to protect stragglers. A wolf pack can also take down an adult bison. Wolves frequently test even the largest bison for weaknesses; usually several wolves may pursue a bison and attempt to bring it down after the bison has succumbed to exhaustion or wounds from the wolves' bites.

Their mating habits are polygamous: dominant bulls maintain a small harem of females for mating. Individual bulls "tend" females until allowed to mate, following them around and chasing away rival males.

Juveniles are lighter in colour than mature bison for the first three months of life. The mating season is in middle to late summer, and as late as September in northern ranges. Gestation is 285 days, generally allowing the calves a springtime birth.