Idaho’s occurrence databases hold 607 beaver records, ranking ninth among the 80 mammals tracked in this batch. That reflects how often people report the animal or its sign, not how many beavers actually work Idaho’s streams.
Mountain drainages and irrigation-fed valleys
Idaho’s beaver records split between two different kinds of water. In the east, Caribou-Targhee National Forest holds beaver ponds strung along lodgepole pine and aspen drainages near the Yellowstone and Teton high country. Further west, Sawtooth high lakes and the slower irrigation canals and side channels threading the sagebrush valleys of the Snake River Plain give beavers the calm water they need in country that otherwise looks too dry and open for a species built around dams.
The rodent that once got parachuted into the backcountry
A beaver’s dam-building habit is what actually shapes its habitat instead of just occupying it: felled aspen and willow slow a stream into a pond, and the pond then floods new ground for the beaver’s own lodge and food cache. Idaho leaned on that instinct directly in 1948, when state wildlife managers relocated nuisance beavers out of the McCall area by dropping them from a plane in wooden crates into the roadless Chamberlain Basin, where the animals were meant to dam creeks and hold water for the backcountry on their own.
Spring records, then a steadier pace
Idaho’s monthly reports jump in April and May before settling into a lower, steadier rate through the rest of the year. That early peak lines up with beavers repairing winter-damaged dams and moving more in daylight as ice breaks up, not with any real jump in how many beavers Idaho actually has.
Status in Idaho
NatureServe ranks the beaver S4, Apparently Secure, in Idaho, and it’s native across the state’s forested and irrigated drainages alike. Few Idaho mammals shape their own habitat as directly, since every dam a beaver builds creates open water and wetland edge that a long list of other species depends on.
Full species profile
