Description: Adults are 18 - 40 inches long. Most snakes encountered are generally 18 - 28 inches long. Neonates are 7 - 10 inches. A medium-sized slender snake with a head barely wider than the neck and keeled dorsal scales.Ground color is gray, brown or black. There is distinct yellow or orange stripe on the back and a light stripe along the lower part of each side on the 2nd and 3rd scale rows. There may be small alternating dark spots on the sides, most noticable on juveniles. The throat is white or yellow, sometimes bright yellow. The underside is bluish or greenish sometimes with pink or yellow marks.

Habitat: Creeks, streams, small lakes and ponds, in woodland, brush and forest and grassy ecotones. Seems to prefer shallow rocky creeks and streams. When found in muddy ponds there are usually rocky outcrops nearby.

Range: Diablo Range Gartersnake, is endemic to California. Thamnophis atratus zaxanthus occurs in the inner Coast Range from Napa and Solano to Santa Barbara counties and the Santa Lucia Range.

Found in these States: CA

Diet: Probably eats mainly amphibians and their larvae, including frogs, tadpoles, and aquatic salamander larvae (newts) but small fish are also eaten, and possibly small rodents. Leeches are also consumed. Adults tend to forage actively. Neonates are sit-and-wait foragers. Juveniles practice both types of foraging.

Reproduction: Courtship has been observed during March and April. Females are ovoviviparous - they carry the eggs internally until the young are born live from late summer to early fall.

Status: Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.

Taxonomy: