How to Identify Bison in Montana

Bison are massive animals. Adult males typically weigh 1,500 to 2,000 pounds and stand 5.5 to 6 feet tall at the shoulder. Females are smaller, usually 800 to 1,000 pounds and 4.5 to 5 feet tall. Both sexes have a thick, dark coat that ranges from dark brown to nearly black, and both have short curved horns that curve forward. The most distinctive feature is the large hump over the shoulders, which gives the front half of the animal a chunky, powerful appearance. The hind quarters slope downward, making the profile instantly recognizable.

Bison coats are dark, shaggy, and thick. In summer, they shed heavily and appear sleeker but still dark. In winter, the coat thickens dramatically, giving them a massive, woolen appearance. Young calves are born reddish-brown or tan in spring and gradually darken over their first year. Adult coloring settles into a uniform dark brown or black. If you see a large dark shaggy animal in Montana fields or grassland, the coat thickness and color alone often confirm it is a bison.

Both male and female bison have short curved horns, typically 12 to 20 inches long. The horns curve forward and inward, forming a shape that is distinctive among North American hoofed mammals. Elk have much longer pointed antlers that are often branched. Bighorn sheep have coiled horns that spiral backward. Cattle in the region may have horns, but they are longer, thinner, and shaped differently. Bison horns are thick at the base, taper along their length, and curve distinctly forward.

Cattle and bison are both large grazing mammals but are easy to tell apart. Bison have a massive shoulder hump and dark thick coat, while cattle lack the hump and typically have smoother shorter coats. Bison heads are larger and more massive with darker coloring. If an animal is grazing in an open area and you see the thick dark shaggy coat, the shoulder hump, and the overall blocky front-heavy build, it is bison. Cattle appear more uniform in body shape and do not have the hump.

Focus on three key features: the shoulder hump, the dark shaggy coat, and the size. No other large animal in Montana combines all three. Elk have tall branching antlers and a lighter colored coat, no hump. Moose are taller and have broader flatter antlers. Black bears are smaller and brown or black depending on the individual. Bighorn sheep are much smaller and live in mountains. When you see a massive dark animal with a hump grazing on grassland, it is almost certainly a bison.

Males and females have the same basic features but differ in size and sometimes horn robustness. Males are significantly heavier and more muscular, with thicker necks and more prominent shoulder humps. Females are smaller and more streamlined but still retain the hump and thick dark coat. Both have horns, though a male's horns may appear more robust. In a group, the largest animals with the most massive builds are almost certainly males.

Bison move with a powerful, deliberate gait. Despite their size, they can run up to 35 miles per hour when threatened. When grazing, they move slowly and deliberately, staying low to the ground with their heads down. When startled, they may gallop or charge. A massive dark shaggy animal moving with this combination of power and bulk is unmistakably a bison. Elk and moose move with longer strides, and smaller ungulates bounce or trot.

Bison leave large hoof prints, typically 4 to 5 inches wide, arranged in a pattern matching their gait. The prints are rounder and larger than those of elk or cattle. Bison also create well-worn trails through grassland by repeatedly traveling the same routes. They wallow in mud or dust during warm months, leaving shallow circular depressions 10 to 20 feet across where the soil is disturbed. Dung is large and fragmented. In Montana, you may find these signs near Yellowstone or in managed bison areas before you see the animals themselves.