Snakes and spiders in Mariposa County, California
Mariposa County, home of Mariposa, has 12 snake and 17 spider species on record, from 323 licensed snake and 181 spider records. Venomous species here: the western rattlesnake and the western black widow.
Are there venomous snakes or spiders in Mariposa County?
Yes. The western rattlesnake: 44 licensed records, 1% of all California records of it. The western black widow: 10 licensed records, 1% of all California records of it.
What snakes are in Mariposa County?
In all, 12 snake species are on the Mariposa County list. The most recorded are the western terrestrial garter snake (57), the western aquatic garter snake (51) and the western rattlesnake (44).
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Western terrestrial garter snake Thamnophis elegans | 57 | 0% |
| 2 | Western aquatic garter snake Thamnophis couchii | 51 | 1% |
| 3 | Western rattlesnake venomous Crotalus oreganus | 44 | 1% |
| 4 | Common garter snake Thamnophis sirtalis | 34 | 1% |
| 5 | California mountain kingsnake Lampropeltis zonata | 28 | 5% |
| 6 | Striped racer Masticophis lateralis | 24 | 2% |
| 7 | Gopher snake Pituophis catenifer | 22 | 0% |
| 8 | Ring-necked snake Diadophis punctatus | 20 | 1% |
| 9 | Northern rubber boa Charina bottae | 15 | 2% |
| 10 | California kingsnake Lampropeltis californiae | 9 | 0% |
| 11 | Eastern racer Coluber constrictor | 7 | 1% |
| 12 | Sharp-tailed snake Contia tenuis | 7 | 1% |
When are snakes out in Mariposa County?
Observation records of snakes in Mariposa County run mostly April through September, peaking in June with 24% of them; across California the peak is May.
What spiders are in Mariposa County?
In all, 17 spider species are on the Mariposa County list. The most recorded are Colonus hesperus (27), the western parson spider (15) and the western lynx spider (14).
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Colonus hesperus | 27 | 4% |
| 2 | Western parson spider Herpyllus propinquus | 15 | 8% |
| 3 | Western lynx spider Oxyopes scalaris | 14 | 1% |
| 4 | Koch's wolf spider Alopecosa kochi | 12 | 1% |
| 5 | California flattened jumping spider Platycryptus californicus | 11 | 9% |
| 6 | Hirsute paradise spider Habronattus hirsutus | 11 | 5% |
| 7 | Tawny dwarf tarantula Megahexura fulva | 11 | 12% |
| 8 | Western black widow venomous Latrodectus hesperus | 10 | 1% |
| 9 | Marbled cellar spider Holocnemus pluchei | 6 | 1% |
| 10 | Sixspotted orbweaver Araniella displicata | 4 | 2% |
| 11 | Johnny Cash tarantula Aphonopelma johnnycashi | 3 | 9% |
| 12 | Oregon paradise jumping spider Habronattus oregonensis | 2 | 1% |
| 13 | California funnel-web spider Calisoga longitarsis | 1 | 1% |
| 14 | Cone-shaped orbweaver Cyclosa conica | 1 | 1% |
| 15 | Johnson jumper Phidippus johnsoni | 1 | 0% |
| 16 | Giant crab spider Olios giganteus | — | — |
| 17 | Ribbon jumping spider Metacyrba taeniola | — | — |
When are spiders out in Mariposa County?
Observation records of spiders in Mariposa County run through most of the year, peaking in May with 18% of them; across California the peak is April.
Common in California, not on the Mariposa County list
Among the snakes most recorded across California, these do not reach the county list: the aquatic garter snake (3,727 statewide), the sidewinder (1,923 statewide), the two-striped garter snake (1,620 statewide), the western shovel-nosed snake (1,482 statewide) and the glossy snake (1,425 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Among the spiders most recorded across California, these do not reach the county list: the bold jumper (2,606 statewide), the half-edged wall jumping spider (2,178 statewide), Steatoda nobilis (1,914 statewide), the false black widow (1,201 statewide), the buttonhook leafbeetle jumping spider (825 statewide) and Habronattus pyrrithrix (800 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Mariposa County
Rattlesnakes are on the county list, and so are harmless species often taken for them: the gopher snake. Coral snakes are not on the California list, but GBIF holds 3 coral snake records of any license in California (Sonoran coralsnake 3): treat any snake like this as venomous until identified. Harmless species often taken for them here: the California mountain kingsnake.
Mariposa County among California counties
By licensed snake records Mariposa County ranks 41st of 58 California counties with any.
Other California counties with their own page: San Diego County, Lassen County, Shasta County, Riverside County, San Bernardino County, Humboldt County, Sonoma County and San Mateo County.
The whole state: venomous species in California, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.