Although the grizzly or brown bear, Ursus arctos, once occurred throughout western North America, Europe, and Asia, its distribution has been greatly reduced. In North America, for example, the brown bear now occurs only in Alaska, parts of Canada, and in the northwestern United States. Unfortunately, the brown bear was extirpated (eliminated) from Utah in the 1920s. Because of the drastic decline in brown bear numbers and distribution, the U.S. Fish and Wildlife Service has listed it as threatened in the lower 48 states.

The brown bear varies in color from yellow to dark brown, and many body hairs have white tips, which gives the bear a grizzled appearance (hence the name grizzly bear). Brown bears have a hump above the shoulders and a concave facial profile. They are extremely large, with exceptional individuals reaching a size of over 1500 pounds.

Brown bears are omnivores, but the majority of their diet is composed of plant matter. The brown bear breeds in the spring, but embryo implantation is delayed until late fall. Young are born in the winter, while the mother is dormant, and the average litter size is two cubs (although a litter can contain from one to four cubs).