Inhabits a wide variety of coastal marine and freshwater habitats, including streams, lakes, ponds, swamps, marshes, estuaries, beaver flowages, and exposed outer coast. In Southeast Alaska, river otters avoided clearcuts of 5 to 20 years old, and preferred beaches with convex shorelines, short intertidal lengths and bedrock substrate (Larsen 1983). The predominant vegetation types used in Southeast were uneven aged old- growth dominated by hemlock/spruce and hemlock (Woolington 1984). Activity is typically confined to within 100 ft of the shore, however females move inland to establish natal denning sites within 0.5 miles of the shore near small streams (Larsen 1983, Woolington 1984). In old growth habitats natal dens occurred on well- drained sites near streams, which were used as corridors for travel between the den site and foraging areas on the coastline (Reid et al. 1994).
Larsen, D.N. 1983. Habitats, movements, and foods of river otters in coastal southeastern Alaska. M.S. thesis. Univ. of Alaska, Fairbanks, AK. 149 p.
Reid, D.G., T.E. Code, A.C.H. Reid and S.M. Herrero. 1994. Spacing, movements, and habitat selection of the river otter in boreal Alberta. Can. J. Zool. 72(7):1314-1324.
Woolington, J.D. 1984. Habitat use and movements of river otters at Kelp Bay, Baranof Island, Alaska. M.S. thesis, University of Alaska, Fairbanks. 147 pp.