California
Snakes in San Francisco County
18 species have been documented here, 2 of them venomous.
Venomous snakes in San Francisco County
Full guide & what to do if bitten →
Prairie RattlesnakeCrotalus viridisVenomousHeavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
Red Diamond RattlesnakeCrotalus ruberVenomousHeavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
Every snake recorded in San Francisco County

Western Terrestrial Garter Snake
Thamnophis elegans
Harmless

Gopher Snake
Pituophis catenifer
Harmless

Aquatic Garter Snake
Thamnophis atratus
Harmless

Ring-necked Snake
Diadophis punctatus
Harmless

North American Racer
Coluber constrictor
Harmless

Common Garter Snake
Thamnophis sirtalis
Harmless

Prairie Rattlesnake
Crotalus viridis
Venomous

California King Snake
Lampropeltis californiae
Harmless

Eastern Kingsnake
Lampropeltis getula
Harmless

Northern Rubber Boa
Charina bottae
Harmless

Lema's Ground Snake
Lygophis dilepis
Harmless

Sonora straminea
Harmless

Northwestern Garter Snake
Thamnophis ordinoides
Harmless

Red Diamond Rattlesnake
Crotalus ruber
Venomous

Common Coachwhip
Masticophis flagellum
Harmless

Common Sharp-tailed Snake
Contia tenuis
Harmless

Sierra Garter Snake
Thamnophis couchii
Harmless
No photo
Mexican Whip Snake
Masticophis lineatus
Harmless
Compiled from verified GBIF & iNaturalist observations. Informational only.