February 25, 1806, at Fort Clatsop, Oregon.

The smallest tree squirrel in its range. Rust red to grayish red above, brightest on sides; white or grayish white below. Tail similar to back color, but outlined with broad black band edged with white.

Often abundant in any kind of forest: natural coniferous forests, pine plantations, mixed, or hardwood forests; often around buildings.

Throughout much of Alaska and Canada; in U.S., south through Rocky Mountain states; in East, south to Iowa, northern Illinois, northern Indiana, northern Ohio, northern Virginia, and through Alleghenies.