The Cervidae Family includes deer and their allies, including moose, elk, and caribou. Member of this family occupy a wide range of habitats, from arctic tundras to tropical forests, and can be found over most of the world. All have slender legs. Most are brown or gray in color, with white spots characterizing the young, and in a few species, the adults. In all but one genus of cervids, at least the males have antlers.

The Mule Deer, while closely related to the eastern species-the white-tailed deer, are remarkably distinct in their biological, ecological, and behavioral attributes. It carries its thin, black-tipped tail drooped, unlike the uplifted, bushy white tail of its cousin. They have a distinctly different gait from the leisurely, graceful leaps of the white-tail. When startled, a Mule Deer will move in a series of stiff-legged jumps with all four feet hitting the ground together.

Mule Deer are usually a dark gray-brown, with a small white rump patch and a small, black-tipped tail. Their large ears are distinctive. Their antlers are normally smaller and branch to form 2 equal forks, while the male White-tailed Deer has forward curving antlers with a number of points (tines) branching from the main beam.