An Ultimate Ungulate Fact SheetReturn to Artiodactyla

Kingdom: Animalia
  Phylum: Chordata
    Class: Mammalia
      Order: Artiodactyla
        Family: Bovidae
          Subfamily: Caprinae
            Genus: Oreamnos

Oreamnos americanus

      Rocky Mountain goat


Oreamnos americanus [de Blainville, 1816].  
Citation: Bull. Sci. Soc. Philom. Paris, 1816:80.
Type locality: USA, Washington, Mt. Adams.

Click on the pictures above for a larger view of the photographs

General Characteristics

Body Length: 140-155cm / 4.7-5.1 ft.
Shoulder Height: 80-90 cm / 2.6-3 ft.
Tail Length: 10 cm / 4 in.
Weight: 56.7-69 kg / 124-152 lb.

The short, white woolly summer coat is replaced in winter by shaggy dense yellowish pelage.  During spring, the molt makes these animals look extremely raggedy.  A small ridge of long, soft hair on the neck forms a hump.  A beard is present on the chin in both sexes.  The bear-like body is supported by muscular legs, ending with hoofs specially configured for mountain life.  The black eyes and nose contrast greatly with the otherwise white head.  The black, slightly curved horns are found in both sexes, and grow 20-25 cm / 8-10 inches long.

Ontogeny and Reproduction

Gestation Period: 175-180 days.
Young per Birth: 1, rarely 2.
Weaning: At about 3 months.
Sexual Maturity: At about 30 months.
Life span: Up to 18 years.

Mating occurs from November to January, with the births taking place in late May and early June.  Kids are able to follow their mothers within a week, and, once weaned, are driven away by their mothers as the next young is born.

Ecology and Behavior

Rocky Mountain goats are most active in the late afternoon and early morning, and frequently continue grazing throughout the night.  Movements throughout the 24-hour day generally cover several hundred meters / yards.  Resting spots are often shallow depressions excavated using the front feet, which they also use when searching for salt.  Mountain goats are renowned for their exceptional speed and agility on steep terrain, and have been known to cover over 450 vertical meters / 1,500 vertical feet in a time span of just 20 minutes.  Home ranges average about 23 square kilometers in size, although in winter, these become much smaller.  Population densities vary widely (up to 14 animals per square kilometer), although the average figure is thought to be between 1 and 2 animals per square kilometer.  The rare fights between rival males are extremely violent, often causing serious injury or death.  Opponents thrust their sharp horns at each others flanks and rump in an attempt to gore the soft flesh.

Family group: During the warmer months, groups of less than four animals are normal, while adult males are frequently solitary.  However, during the winter these groups join together to form large herds.
Diet: Grasses, leaves, coniferous trees.
Main Predators: Cougar, brown bear.


Mountainous regions in western Canada and the northwestern United States.

Range Map (Compiled from Shackleton, 1997)

Conservation Status

The Rocky Mountain goat is currently not in danger.


Despite its name, this ungulate is not a true goat, being more closely allied with the chamois and gorals than tot he genus Capra.  Due to its inaccessible habitat, the Rocky Mountain goat has been less affected by human activity than any other large North American game animal.  Oros (Greek), genitive oreos, a mountain; amnos (Greek) a lamb.  -anus (Latin) suffix meaning belonging to.

Literature Cited

Geist, V. 1990.  Rocky Mountain goats (Genus Oreamnos).  In Grzimek's Encyclopedia of Mammals.  Edited by S. P. Parker.  New York: McGraw-Hill.  Volume 5, pp. 497-505.

Nowak, R. M. [editor]. 1991. Walker's Mammals of the World (Fifth Edition). Baltimore: The Johns Hopkins University Press.

Shackleton, D. M. [Editor] and the IUCN/SSC Caprinae Specialist Group.  1997.  Wild Sheep and Goats and their Relatives.  Status Survey and Action Plan for Caprinae.   IUCN: Gland, Switzerland and Cambridge, UK.

Wilson, D. E., and D. M. Reeder [editors]. 1993. Mammal Species of the World (Second Edition). Washington: Smithsonian Institution Press.  Available online at

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© Brent Huffman,
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