Type.—Obtained on Mt. Rainier, 6,000 ft., Pierce County, Washington, by A. K. [Fisher] on August 11, 1897; type in United States National Museum.
Measurements.—A young adult male from Stevens Pass, King County, measures: total length 773; length of tail 221; hind foot 93; ear 27.
Distribution.—The Cascade Mountains, ranging from Mt. Baker (W. W. D.) and Mt. Chopaka ([Taylor] and [Shaw], 1929: 15) south to Mt. Adams ([Taylor] and [Shaw], 1929: 15).
Description.—The hoary marmot is the largest of the American marmots; adults are 28 inches or more in length, of which the tail makes up about 8 inches. The pelage is dense and rather woolly. The upper parts are not frosted with white-tipped hairs, but are gray washed with blackish. The head is blackish with white facial markings, and the shoulders, legs and underparts are gray. The tail is dark reddish brown.
Hoary marmots range from Alaska south to Washington and Idaho. [Howell] (1915: 57-67) recognizes seven races of this species.
Fig. 84A. Distribution of marmots in Washington. A. Marmota monax petrensis. B. Marmota flaviventris avara. C. Marmota caligata cascadensis. D. Marmota olympus.
This mammal of the higher altitudes rarely goes below the Hudsonian Life-zone. It is most common in the talus slides at the lower edge of the Arctic-Alpine Life-zone. Like other marmots, it prefers to live amid loose boulders. The steep talus or "scab rock" slides in the glacial cirques provide an ideal habitat. The crevices and caves beneath the rocks offer concealment for young and adults. A large boulder with a flat top is usually selected as a look-out. Well-worn trails lead from the talus slides to nearby grassy slopes. When surprised in the open, the hoary marmot exhibits a peculiar bounding run, reminiscent of that of tree squirrels. The short tail "follows through" in the leaps. In the rock slides the hoary marmot is surprisingly agile.