The western jumping mouse, Zapus princeps, occurs in much of the western United States and in western Canada. In Utah, the species is primarily found in the northern and central areas of the state, in mountain meadows near streams or marshes. Like other species of jumping mouse, the body of the western jumping mouse is not very big (about four inches in length), but the hind feet are very large, and the tail is very long (sometimes six inches in length). Amazingly, western jumping mice can jump up to six feet.
The western jumping mouse eats insects during the spring and grass seeds during the summer and early fall. The species hibernates from October to early June in Utah. Western jumping mice breed soon after females awaken from hibernation, and an average of five young are born about three weeks later. The species is primarily active at night.