Brown bear are numerous throughout the area because of good forage conditions and seasonal availability of ample dietary protein in the form of salmon. River runners often see brown bears on the Aniakchak River, often a lot closer than common sense dictates. Brown Bear use dens on the slopes of the volcano and the eastern side of the Aleutian Range in winter, and move to lower elevations in the spring where they concentrate along coastal grassy plains, tideflats, and at the heads of bays. By late summer and early fall the concentration shifts to streams, where the bear fish for salmon. Bears in this region are considerable larger than interior Alaska individuals of the same species.
Up to 300 caribou could visit the Aniakchak area seasonally from calving areas near Port Heiden on the coast. Groups of 10 to 20 of these migratory animals have been seen in the caldera itself. The moose population in the area is at least 250 animals. Other mammals in the area are; wolf, wolverine, fox, and ground squirrel. Marine mammals within the area are limited to sea otters, sea lion, and harbor seal.
Columbia