Mule deer run with a strange gait compared to white-tailed deer. Mule deer run in a stiff-legged jumping motion, actually hopping, over obstacles. They are usually traversing uphill. The mule deer's running style is called stotting.
Sometimes people confuse the white rump of the mule deer with the white tail of the white-tailed deer. Mule deer typically have a very narrow tail with a black tip, so their white rump is easily visible.
Mule deer have a four-chambered stomach.