Yellow-bellied marmots occupy the upland regions of the Western United States and semidesert areas of the Great Basin, except for portions of western and southeastern Utah and southern Nevada. They're often espied in Utah's alpine and subalpine zones.
These ground-dwelling rodents prefer mountain slopes and meadows, making use of rocky places and outcrops. Rocks serve as superstructures for dens and as sunning and observation decks. Burrows, their hiding places and nurseries, can extend 10 to 15 feet into a hillside.
The marmot is heavy-bodied with wide color variation, having yellowish brown to tawny fur and brown feet. As its name implies, a distinguishing feature is the belly, which can actually be yellow, orange or reddish brown. Some animals are almost entirely coal black. Their strong feet and claws are adapted for digging. Adults are 181/2 to 275/8 inches in length, with bushy tails 51/8 to 83/4 inches long. Males are slightly longer and heavier than females.
DIET AND HABITS
Yellow-bellied marmots are basically herbivorous. They eat grasses, alfalfa, forbs, flowers and seeds. Most active in the morning and late afternoon, they can sometimes be seen sunning themselves aboveground. A true hibernator, they are torpid much of the year - from September through May for those at high altitudes. Marmots have a harem social system, with males defending and mating with one or more females, and can be found living in colonies.