Marmots in Rocky Mountain National Park

NPS Photo / Walt Kaesler

Yellow-bellied marmots spend over half their lives in hibernation. They live at high elevations where winters can be extreme. They enter their burrows in the fall and don't emerge until spring, usually in April or May. Marmots are the largest members of the squirrel family and can be two feet in length and weigh up to 11 pounds! Their large body size is an adaptation to the cold, high elevation sites in which they live. Marmots have reddish-brown fur and a yellow belly, from which they get their name. They are related to woodchucks and groundhogs in other parts of the country. Marmots can be seen at high elevations in Rocky Mountain National Park.