Mammals

American Beaver Castor canadensis Feb, Apr – Dec North America's largest rodent and Oregon's state animal, a dam-building engineer of streams and ponds that is most active at dusk and… American Pika Ochotona princeps May – Oct A small, round, tailless rabbit relative that lives in high rock slopes, squeaks from the boulders and stores hay for winter. Douglas’s Squirrel Tamiasciurus douglasii Apr – Nov A small, loud tree squirrel of conifer forests that scolds hikers from the branches and leaves big piles of stripped cone scales. Eastern Fox Squirrel Sciurus niger Jan – Apr, Jul, Sep – Nov A large, orange-tinged tree squirrel from the eastern US, brought west and now common in Oregon towns and orchards. Here it is… Golden-mantled Ground Squirrel Callospermophilus lateralis Jun – Oct A stocky ground squirrel with a coppery head and shoulders and a white side stripe edged in black. Unlike a chipmunk, it… Mule Deer Odocoileus hemionus Mar – Oct Mt. Hood sits where two forms of this deer meet: black-tailed deer on the wet west side and mule deer on the… North American River Otter Lontra canadensis Feb – May, Jul – Nov A sleek, playful swimmer of rivers and lakes, with webbed feet and a thick, tapering tail. Mostly active at night but sometimes… Snowshoe Hare Lepus americanus May – Dec A forest hare with oversized furry hind feet that turns white in winter in many places and hides in dense young conifers… Townsend’s Chipmunk Neotamias townsendii Apr – Oct Oregon's largest chipmunk, a dark, dull-striped resident of west Cascades forests that is often heard calling before it is seen. Yellow-bellied Marmot Marmota flaviventris Jul – Aug Oregon's largest squirrel, a stocky marmot of rock piles and meadows that whistles an alarm and spends most of the year hibernating.