Mule deer’s defining characteristic are their large ears, which are about three-fourths the length of the head. They have a distinctive black forehead, or mask, that contrasts with a light gray face. In the summer, mule deer are tannish-brown and in the winter are brownish-gray in color. They have a white rump patch and a small white tail with a black tip. When running, they bound in a motion called “stotting,” in which all four hooves push off the ground at the same time (nwf.org).