Three species of bighorn sheep are native to North America:  the desert, California, and Rocky Mountain bighorn sheep.   Bighorn sheep are among the best known icons of the American West -- often visible atop steep mountain tops and spires with their curled horns.  

Of these, Rocky Mountain bighorn sheep were once abundant in central Idaho and other portions of the northern Rockies; but entire populations have been lost and others decimated, mainly because of diseases spread from contact with domestic sheep grazing on public lands. 

Because bighorn sheep are gregarious animals capable of travelling large distances -- some have been tracked over several miles across high country in a single day -- they often will come into contact with domestic sheep grazing on Forest Service and BLM lands in bighorn habitats. 

Maintaining a large degree of separation by keeping domestic sheep out of bighorn areas is thus vital to preserving this iconic species.