Thirty nine species of mammals have been documented in Denali National Park and Preserve. Mammals here range in size from the 1200 pound moose to the 1.5 gram tiny shrew. A goal for many visitors to the park is to see the "big five". On a ride along the park road visitors can see a moose browsing in a stand of willow, caribou resting on a snow patch to avoid insects, Dall's sheep high on the hillsides, a wolf trotting across the tundra, or a grizzly bear feeding on ripening blueberries. Many other mammals in Denali are less obvious but no less interesting and important.
Denali's summers are short and winters extreme. Mammals here have many adaptations that help them survive. Rodents and shrews make up more than half the species of mammals. Many keep busy in summer gathering great quantities of food to sustain them through the winter. Red squirrels store spruce cones in piles and burrows on the forest floor. The smallest mammals, the mice, voles, shrews and lemmings depend on food stockpiles while they stay active under a protective layer of winter snow. The largest rodent, the beaver, will store a brush pile at the bottom of its pond that can be accessed under water from its lodge when the pond is frozen over.
Grizzly bears, black bears, hoary marmots, and arctic ground squirrels avoid the winter by hibernating. To build up body fat reserves needed for hibernation they eat extensively in late summer.
Camouflage is an adaptation used by two of Denali's mammals. To blend in with the summer vegetation, the fur of snowshoe hare and short tailed weasel (ermine) is brown. Their fur changes to white to blend with the winter snow.