Rocky Mountain sheep, (Bighorn) wild sheep of W North America, formerly plentiful in mountains from Canada to Mexico. Indiscriminate hunting, disease, and scarcity of food have reduced its numbers, and in some areas it has been exterminated. It is a heavy, grayish brown animal, with a conspicuous whitish patch on its hindquarters; the male has heavy, curling horns, while the female has short, straight spikes. One type of bighorn lives at high altitudes in the W United States and another in desert regions. Alaskan types are the Dall's, or white, sheep and the Stone's, or black, sheep. Bighorn sheep are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Bovidae.

The distinctive feature of Bighorn Sheep is the massive brown spiral horns which, in rams, curls back and down close to the head with tips projecting forward and outward just below the eyes. The ewe’s horns are shorter and simply curl back laterally from the crown. The coat is smooth and close to the body contours. The dorsal colour is wood brown with darker chocolate brown on the chest, face and legs. The lower belly, backs of the legs, muzzle and large rump patch are ivory white. Males weigh 130 – 156 kg. Females are much smaller than males.

All time record: Score 206 2/8 - Alberta, GMU 438 - 11/95 (source - www.BlueWaterBigGame.com)