April 24, 1806, near Roosevelt, Klickitat County, Washington.
Spiny; scales on back of thigh abruptly smaller. Scales on back same size as those on sides and belly. Olive, brownish, or black, with pattern of paired blotches or wavy crossbars down back and occasionally some striping. Undersurfaces of legs yellowish orange. Blue patches on sides of belly; adult male has blue patch on throat. Length: 6-9.25 in (15.2-23.5 cm).
Rocky and mixed forest areas from sea level to above 9,000 ft (2,700 m). Adapts to wide variety of conditions but not to desert. Frequents stone fences, fence posts, old buildings.
Central Idaho south through Nevada and west to the Pacific coast.