Although principally nocturnal, mountain beavers are not infrequently active by day, especially in the fall. At this season they harvest food and spread it on logs to dry. The cured hay is removed to their burrows for nesting material and food. In winter mountain beavers are more restricted in habits and are rarely seen by day. Presumably they feed on stored food at this time but they forage somewhat. In winter they eat such evergreen shrubs as salal (_Gaultheria shallon_) and Oregon grape (_Berberis nervosa_). They eat also the bark of trees, especially that of the willow (_Salix_). Under cover of snow, in the mountains, they burrow to some extent and pack excavated earth in snow burrows. The melting of the snow in the spring reveals the earth core, six to eight inches in diameter and two to four feet long. Several such earth cores were forked, showing that part of the earth had been pushed into a branching burrow. [Illustration: FIG. 122. Distribution of the mountain beaver in Washington. A. _Aplodontia rufa rufa._ B. _Aplodontia rufa rainieri._] The mountain beaver holds its food in its forefeet, squirrel-like, when it eats. Its food consists of the leaves and bark of woody plants and entire herbs, including roots. The mountain beaver is the only mammal so far as known that eats the bracken fern. It feeds on the branches of coniferous trees, including Douglas fir, red cedar, and hemlock. Such thorny species as the blackberry, blackcap and devil's club are eaten. The odiferous skunk cabbage and the stinging nettle are on its bill of fare. A list of its food would include most plants found in its habitat, and we know of no species that it refuses as food. The mountain beaver is more of a nuisance than a pest. In most of its range there is but little farming although where crops are raised the mountain beaver may do some damage. It undermines roads and trails and defiles springs and streams. Control is simple for the animals readily enter steel traps set in their burrows. =Aplodontia rufa rufa= (Rafinesque) _Anisonyx? rufa_ Rafinesque, Amer. Monthly Mag., 2:45, November, 1817. _Haplodon rufus_ True, Proc. U. S. Nat. Mus., 7 (1884):596, 1885. _Aplodontia rufa_ Merriam, Ann. New York Acad. Sci., 3:316, May, 1886. _Aplodontia olympica_ Merriam, Proc. Biol. Soc. Washington, 13:20, January 31, 1899 (type from Lake Quiniault, Grays Harbor County, Washington). _Aplodontia rufa grisea_ Taylor, Univ. California Publ. Zoöl., 12:497, May 6, 1916 (type from Renton, King County, Washington). _Aplodontia rufa rufa_ Taylor, Univ. California Publ. Zoöl., 12:497, May 6, 1916. _Type._--None. Based on a description by Lewis and Clark. Taylor (1918: 455) regarded as typical specimens collected at "Marmot, Clackamas County, Oregon (western slope of Mount Hood, not far from the Columbia River)." _Racial characters._--Size small; skull small.