大角羊
Bighorn sheep ("Ovis canadensis") were once very numerous in western United States and were an important food source for humans. The "Sheep eaters", a band of Shoshone people, lived year-round in Yellowstone until 1880. Their principal food was bighorn sheep and they made their bows from sheep horns. By 1900, during an "epoch of relentless destruction by the skin hunters", bighorn numbers were reduced to a few hundred in the United States. In 1897 about 100-150 were estimated to be present in the park. By 1912, despite a disease (scab) contracted from domestic sheep, bighorns in the park had increased to more than 200 and travelers could find them with fair certainty by devoting a few days to searching around Mount Everts, Mount Washburn or other well-known ranges. In winter, small bands of sheep could then be seen every day between Mammoth and Gardiner. Bighorn sheep usually live 10–15 years in the wild.