Similar to other ground squirrel species, Spermophilus washingtoni individuals have short legs and small, rounded ears. The tail is short (32-65 mm), the rounded eyes are set high on the head, the postorbital processes are well developed, and the zygomatic arches expand posteriorly. The cheek teeth are high crowned. Greyish-white spots about 4 mm across mark the smoky-grey base color on their backs. The underside is grayish-white and extends up the sides of the body to a line connecting the shoulder and thighs. There is a white eye-ring. Weight varies seasonally between 120 and 300 grams. Males are slightly larger than females, with total body lengths of males and females ranging from 185 to 245 mm. Spermophilus washingtoni can be distinguished from other grounds squirrels (S. columbianus and S. beldingi) in the same area because they are smaller, with smaller ears and a spotted pelage, which the other two species lack. Spermophilus washingtoni have a hind foot of less than 43 mm, whereas the other two species have longer hind foot lengths. (Tomich, 1982; Verts and Carraway, 1998)