There are plenty of ungulates in Yellowstone, too — that’s the formal term for vegetarian animals with hooves. Elks are the most common throughout the park, but animals such as moose and bison also live there. In fact, Yellowstone is the only part of the U.S. that has remained a constant home to bison from the prehistoric era to the present. Photo credit: Stephen Pribut/Wikipedia | CC BY-SA 3.0