It is a common but secretive species whose range extends from southern British Columbia and throughout Washington, Oregon, Nevada, Utah, Idaho, and Wyoming and into western Montana and northern Arizona and Missouri.

Initially described in 1852 by Baird and Girard, the Western skink is named for Dr. Avery Judd Skilton (1802–1858), an American physician and naturalist,[6] who collected the first specimens.

The exact taxonomy within this group has yet to be conclusively determined, and may need revision following DNA analysis research.There are three recognized subspecies, including the nominotypical subspecies:[2] The most common is Skilton's skink, which occurs throughout the western United States west of the Rocky Mountains and in southern British Columbia, Canada.

The western skink is a secretive and very agile lizard that forages actively through leaf litter and dense vegetation, preying upon small invertebrates including spiders, a variety of insects and sow bugs.

Western skink females construct nest chambers that are several centimeters deep in loose moist soil.

Frequents grassland, broken chaparral, pinon-juniper and juniper-sage woodland, and open pine-oak and pine forests.

A second pale stripe, starting on upper jaw, occurs low on each side and is separated from the first by a broad dark brown or black band originating on the side of head and usually extending well out onto the tail, though this band can be disrupted if the tail is lost and regrown.

[10] Western skinks can be found from southern British Columbia, Canada, to the tip of the Baja California Peninsula, and throughout most of Great Basin to extreme Northern Arizona; central Utah to the Pacific Coast.

The species is apparently absent from the floor of San Joaquin Valley (they have been observed in rural areas of southeast Lodi, CA), central Sierra Nevada (except a few scattered locations in the foothills where they are very common), and lowland deserts of California.

[9] Throughout their range, they may be targeted by a range of predators, especially young animals honing their hunting skills, including black bear cubs, bobcats, coyotes, gray, red and swift foxes, least weasels and pumas, as well as domestic and feral cats and dogs.

Skinks can perform autotomy; if seized by a predator its tail is deliberately cast and wriggles violently attracting attention while the lizard may escape.

Adult skinks usually become inactive by early fall but juveniles extend their period of activity several weeks.

Western skinks' eggs hatch in the months of July and August; the exact time differs by geographic location.