No squirrel in Oregon is bigger than the yellow-bellied marmot, a heavy, short-legged rodent with a bushy tail, small furry ears, a reddish brown back and a yellowish belly. It lives in rocky places with plenty of green plants close by, digging its burrows among boulders, talus or log piles where it can dash for cover.
Marmots are known for their whistles. One sharp, loud whistle warns the rest of the colony of danger, which is why early settlers called them whistle pigs. They also scream when frightened or excited and chatter their teeth as a threat. A colony is usually one male, several females and their young. They graze on grasses and wildflowers early in summer and switch to seeds later in the season.
Much of a marmot’s life is spent asleep. In central Oregon they come out of hibernation in late winter and stay active for only about four and a half to five months, with adults going back underground by the end of July. Mt. Hood marks the western edge of the species’ Oregon range, which lies east of a line from Mt. Hood to the Crater Lake area. Look for marmots sunning on rocks near meadows on the drier side of the mountain early in summer.
How to identify it
A large, stocky ground-dwelling squirrel with short legs, a short bushy tail, small fur-covered ears, a grizzled reddish brown back and a yellowish belly. Usually seen sitting up on a rock or near a burrow, and often heard before it is seen giving a loud whistle.
Look-alikes
It is the largest squirrel in Oregon, so the chipmunks and ground squirrels that share rocky slopes are easy to tell apart by size alone.
Habitat
Open, rocky places with boulders, talus or rock piles next to lush plants, from valleys up to alpine slopes. In Oregon it lives east of a line from Mt. Hood to the Crater Lake area, outside the Columbia Basin.
Sightings in the forest
60 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on August 26, 2026. See them on iNaturalist →