Bighorn

See also: National Parks and Monuments (table)

Bighorn,

river, 461 mi (741 km) long, formed in W central Wyo. by the confluence of the Wind and Pop Agie rivers and flowing north to join the Yellowstone River in S Mont. The Bighorn basin, part of the Missouri River basin project, has several dams that provide for flood control, irrigation, hydroelectricity, and recreation. Boysen and Yellowtail are the principal dams; the lake behind Yellowtail dam is the nucleus of Bighorn Canyon National Recreation Area (see National Parks and Monuments, table). In 1807 a U.S. trading post was established at the mouth of the Bighorn. The battle between the forces of Col. George Custer and the Sioux took place (1876) near the junction of the Bighorn and the Little Bighorn rivers.

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See also: National Parks and Monuments (table)

bighorn

or

Rocky Mountain sheep,

wild sheep, Ovis canadensis, of W North America, formerly plentiful in mountains from SW Canada to N Mexico. Indiscriminate hunting, disease, and scarcity of food enormously reduced its numbers by the mid-20th cent., and in many areas of its former range it was exterminated. Since the late 20th cent., it has been reintroduced into parts of its former range, though its numbers and range remained greatly reduced compared to the early 1800s. The bighorn 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. Two types of bighorn lives at high altitudes in the W United States (one restricted to the Sierra Nevada range) and a third type in desert regions. The similar Dall, or white, sheep, O. dalli, of Alaska, Yukon, and British Columbia, is white to slate-brown; the slate-brown type of British Columbia is also known as the Stone, or black, sheep. Bighorn sheep are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Bovidae.

Bighorn

 

(Ovis canadensis), also bighorn sheep, an even-toed ungulate of the family Bovidae. The male bighorn is about 178 cm long, stands about 105 cm tall at the shoulders, and weighs about 140 kg. Females are much smaller, weighing little more than half as much as the males. The horns of males are about 111 cm long (up to the bend) and about 36 cm in circumference; the horns of females are smaller. Bighorns inhabiting the Far North are very light in coloration; bighorns in the southern parts of the range are various shades of brown.

Bighorns are common in Northeast Asia and North America, as far south as Mexico. There are four subspecies in the USSR: Kamchatka, Okhotsk, Yakutsk, and Noril’sk (Putorana). The animals are gregarious and polygamous. They live on treeless slopes of mud volcanoes and coastal cliffs. They feed on trees, shrubs, grasses, and lichens. Mating takes place in November and December, and the female gives birth to one or, less commonly, two young in May or June. Bighorns are commercially valued for their meat, skin, and horns.

REFERENCE

Mlekopitaiushchie Sovetskogo Soiuza, vol. 1. Edited by V. G. Geptner and N. P. Naumov. Moscow, 1961.