This species is closely related to the Townsend ground squirrel but its habitat is more varied. It is most common in areas of low sage bushes surrounded by grasslands and on extensive grasslands, but occurs also in sandy places, wheat fields, and rocky hillsides. The animals live in colonies, in some places 50 or more individuals to the acre. They occur also as scattered individuals or small colonies in smaller areas of suitable habitat. For example, along the highway from Farmer, Douglas County, to Waterville, a distance of 15 miles, a band of natural grass, 50 feet or less in width, lies between the road and the extensive wheat fields beyond. This strip of natural cover possessed about one _Citellus_ to each 200 feet along most of its length. The squirrels were often seen sitting on rolls of wire drift fence, used to keep snow drifts from the road in winter but in summer rolled into bundles 3 feet in diameter and left standing at intervals of one each 100 feet. The squirrels had constructed their burrow entrances beneath these rolls and used the rolls as look-out posts. At my approach they would dodge into the rolls of wire and, unless scared, remained in the wire roll. By approaching carefully and overturning the rolls I was able to trap and capture a good series of living specimens. Burrows, nests, habits, and food of this species seem identical to those of _townsendii_. Aestivation dates seem to be the same (Scheffer, 1941: 270-279). The hibernation of this species has been discussed in detail by Svhila (1939: 6-10). Food species listed by Scheffer at Wallula (Howell, 1938: 8) are identical to those of _townsendii_ at Kennewick, across the Columbia River (see account of _townsendii_). Scheffer (1941: 270-279) examined 26 pregnant females of this species and found the fetuses to vary from 5 to 11 in number, with an average of 8. =Citellus columbianus= (Ord) Columbian ground squirrel _Description._--The Columbian ground squirrel has the general body proportions, large head, large eyes, low, rounded ears, plump body and short tail of the Townsend ground squirrel, but is much larger. The head and body of an adult measure about 10 inches and the tail about 4 inches. The upper parts are grayish buff mottled with round white dots. The underparts and forefeet are pale ochraceous. The back of the head and neck are gray. The face, thighs and tail are reddish. The Columbian ground squirrel occupies inland mountainous areas from central British Columbia to central Oregon and Idaho and from eastern Washington and Oregon to western Montana and southwestern Alberta. It is closely related to the arctic ground squirrels of the _Citellus parryii_ group, which are in turn related to the Siberian forms, _buxtoni_ and _stejnegeri_.