Desert Bighorn Sheep (Ovis canadensis nelsoni) is a subspecies of bighorn sheep (Ovis canadensis), that is native to the deserts of the Southwestern United States and Northwestern Mexico. The trinomial of this species commemorates the American naturalist Edward William Nelson (1855–1934). The characteristics and behavior of desert bighorn sheep generally follow those of other bighorn sheep, except for adaptation to the lack of water in the desert. They can go for extended periods of time without drinking water.