An adult alpine marmot may stand at 18 cm (7.1 in) at the shoulder. They reach between 42 and 54 cm (17 and 21 in) in length, not including the tail. The body mass is significantly lighter in spring, when these animals weigh 2.8 to 3.3 kg (6.2 to 7.3 lb), than in fall, when they weigh 5.5 to 8 kg (12 to 18 lb). The alpine marmot is sometimes considered the largest squirrel species, although the closely related hoary marmot is sometimes heavier. Its coat is a mixture of blonde, reddish and dark gray fur. While most of the alpine marmot's fingers have claws, its thumbs have nails.