High Quality Content by WIKIPEDIA articles! The snow sheep (Ovis nivicola), or Siberian bighorn sheep, is a species of sheep, which comes from the mountainous areas in the northeast of Siberia. One subspecies, the Putorana Snow Sheep (Ovis nivicola borealis) lives isolated from the other forms in the Putoran mountains. The snow sheep is related to the North American Bighorn Sheep and Dall`s Sheep, and some zoologists consider it a subspecies of this sheep.