Sciurus griseus griseus [Miller], U. S. Nat. Mus. Bull., 128:222, April 29, 1924.
Type.—None. Described from a squirrel seen by Lewis and Clark. Type locality, The Dalles, Wasco County, Oregon.
Measurements.—A female from midway between Satus Pass and Goldendale, Klickitat County, measured: total length 560; length of tail 264; hind foot 76; weight 897 grams.
Distribution.—Southwestern Washington north to the glacial prairies near Tacoma (W. W. D.); the Columbia River Valley of the southern Cascades; the eastern edge of the Cascades north to Lake Chelan ([Taylor] and [Shaw], 1929: 18).
Fig. 88. Distribution of the western gray squirrel, Sciurus griseus, in Washington.
Description.—This is the largest tree squirrel found in Washington. The head and body measure about 12 inches, and the tail about 11 inches. The body is long and slender. The fur is long and soft, that on the tail being exceptionally long. The upper parts are silvery gray and the underparts white.
The western gray squirrel is restricted to the region of the Pacific Coast and ranges from central Washington south to northern Lower California. Three subspecies are recognized, only one of which occurs in Washington. Like the red squirrels, the western gray squirrel is arboreal. Its favored habitat is the oak woods rather than coniferous forest. Its range in Washington is largely regulated by the distribution of oaks, especially the garry oak (Quercus garryana). Altitudinally it ranges from near sea level at Puget Sound to above 2,500 feet elevation in the eastern Cascade Mountains. It seems to be restricted to the Transition Life-zone.