Marin County is in the northern region of the San Francisco Bay Area and provides forests, grassland and aquatic habitats for snakes. Most of the snakes in Marin County are nonvenomous and use constriction to subdue their prey. Only one snake in Marin County is venomous: the northern Pacific rattlesnake. Although the area's nonvenomous snakes do not have venom, some of them still bite when threatened.
The rubber boa, or Charina bottae, is found throughout the coast of Northern California, including Marin County. These snakes are usually one solid color in their dorsal area, such as dark brown and olive, and they have yellowish bellies. Although they live in forested areas, rubber boas prefer aquatic habitats, including slow-moving streams and lakes. As adults, rubber boas reach lengths of 2.6 feet. Rubber boas receive their names from the loose skin on their body. When defending themselves, rubber boas curl up into a ball.
Western Yellow-bellied Racer
Found in coastal counties throughout California, the western yellow-bellied racer, or Coluber mormon, earned its name from the yellow scales on its belly. These snakes grow up to 3 feet in length when they mature. Forests and grasslands are the primary habitats for western yellow-bellied racers. This snake species have the name "racer" because of their quickness. Western yellow-bellied racers do not have rattles, but they shake their tail similarly to rattlesnakes when they feel alarmed.
Sharp-tailed snakes, or Contia tenuis, are found in California's coastal counties and the Sierra Nevada Mountains. This snake lives in habitats with moist soil, but are not water snakes. Sharp-tailed snakes adapt well to cooler environments and are active during the fall and winter. The average length of sharp-tailed snakes is 1 to 2 feet. The primary staples of the sharp-tailed snake's diet are slugs and salamanders. As its name suggests, this snake has a sharp, scale-like tail.
California Mountain Kingsnake
Most California mountain kingsnakes, or Lampropeltis zonata, are found in the Golden State's mountain ranges, but this snake is also seen in Marin County. This snake is called "kingsnake" because it is known for eating other snakes, including venomous species and other California mountain kingsnakes. California mountain kingsnakes have red, black and white rings on its body. This snake can live at elevated heights of more than 9,000 feet; forests are another habitat for this snake. California mountain kingsnakes grow up to 4 feet long.
Northern Pacific Rattlesnake
The only venomous snake in Marin County is the northern Pacific rattlesnake, or Crotalus viridus oreganus. This snake is found in Marin County's forests and grasslands. When hunting, northern Pacific rattlesnakes are able to control the amount of venom they inject into their prey. Northern Pacific rattlesnakes shake their tails when they feel threatened. Adult snakes of this species grow up to 4 feet in length.