The "largest of the ground squirrels" is approximately "30-40 cm in length and has a 8-15 cm bushy-tipped tail" at maturity (Wouding pg 158. 1982). Females are slightly smaller than males, who weigh about 820 grams. This species has a tawny or tan coloring, with reddish or cinnamon colored cheeks, shoulders and head. It also has pale tawny colored underside and legs along with a brown or gray back with some white spots. This squirrel has a white eye-ring and a tail that has brown and black-tipped hairs.
Arctic ground squirrels have two annual molts. The first starts at the hind-end and proceeds to the head in the spring (around June). In the fall, the molt occurs in the opposite direction (starting at the head) and leaves the squirrel with a grayer tone. The spring molt produces a molt-line that is not noticeable in the fall molt.
This species, as does most of the family Sciuridae, has excellent eyesight. They are built for a terrestrial life of digging with heavy bodies and strong forelimbs with big claws. (Wouding, 1982; Banfield, 1974; Macdonald, 1985)
Range mass: 698 to 907 g.
Average mass: 820 g.