Any one of several varieties of rodents, the most common being the woodchuck, Marmota Monax. I find the mountainous varieties more interesting. They live in burrows, and tend to live in colonies. Most are about a foot to two feet long, with brown or yellowish fur. Several varieties in the US include the Hoary Marmot, Marmota Caligata and the Yellow-Bellied Marmot, Marmota Flaviventris. I've often seen these while hiking in the Cascade Range, near Holden Village