In some species the underparts differ little in color from the upper parts, but in other species there is considerable variation. The underparts range from whitish to dark brown, yellowish gray, or reddish orange. The texture of the fur varies from thin to long and thick, with degrees of coarseness. Climate probably influences the thickness of the pelage. Apparently there is only one molt per year, in the early summer.
Marmots generally occupy open habitats such as steppes, alpine meadows, pastures, and forest edge.
They spend most of their life in burrows, which they excavate in well-drained soil and which have several entrances. These burrows usually are over 1 meter in depth, but hibernation burrows may be 5-7 meters deep. Marmots are mainly diurnal and terrestrial, but they occasionally climb into shrubs and trees. During the summer they accumulate fat reserves amounting to about 20 percent of the total body weight, which they live on during the dormant period. They may emerge briefly during spells of mild winter weather.