The forested area of Wind Cave National Park includes scattered groves of ponderosa pine trees with a few hardwoods and one large forested area occupying the western and northwestern sections of the park. Small mammals like the red squirrel, porcupine, and chipmunk are often seen in these areas along with larger mammals like the mule deer and the elk.
The mule deer, while closely related to the eastern species-the white-tailed deer, are remarkably distinct in their biological, ecological, and behavioral attributes. The mule deer evolved in the dry, rugged badlands and mountains of the west. 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. This gait offers two advantages: it allows the deer to out-distance predators in rough terrain, and to see above the thick brush. If necessary, they can turn or completely reverse direction in the course of a single bound.
Other characteristics that distinguish mule deer are the large size of their ears (for which they were named), their overall shape and large size, the form of the antlers and the tail. The mule deer carries its thin, black-tipped tail drooped, unlike the uplifted, bushy white tail of its cousin.