The Dall Sheep (sometimes called Thinhorn Sheep), Ovis dalli, is a wild sheep of the mountainous regions of northwest North America. The sheep inhabit the sub arctic mountain ranges of Alaska, the Yukon Territory, the Mackenzie Mountains in the western Northwest Territories, and northern British Columbia. Dall sheep are found in relatively dry country and try to stay in a special combination of open alpine ridges, meadows, and steep slopes with extremely rugged ground in the immediate vicinity, in order to escape from predators that cannot travel quickly through such terrain.
Male Dall Sheep have thick curling horns. The females have shorter, more slender, slightly curved horns. Males live in bands which seldom associate with female groups except during the mating season in late November and early December. Lambs are born in May. The primary predators of Dall sheep are wolves, coyotes, black bears, and grizzly bears; golden eagles are predators of the young.
During the summer when food is abundant, the sheep eat a wide variety of plants. During the winter diet is much more limited and consists primarily of dry, frozen grass and sedge stems available when snow is blown off, lichen and moss. Many Dall sheep populations visit mineral licks during the spring and often travel many miles to eat the soil around the licks.