Snakes and spiders in Missoula County, Montana
Missoula County, home of Missoula, has 5 snake and 24 spider species on record, from 82 licensed snake and 1,709 spider records. Venomous species here: the western black widow.
Are there venomous snakes or spiders in Missoula County?
Yes. The western black widow: 3 licensed records, 33% of all Montana records of it.
What snakes are in Missoula County?
In all, 5 snake species are on the Missoula County list. The most recorded are the western terrestrial garter snake (36), the northern rubber boa (16) and the eastern racer (12).
| # | Species | Records | Share of Montana records |
|---|---|---|---|
| 1 | Western terrestrial garter snake Thamnophis elegans | 36 | 9% |
| 2 | Northern rubber boa Charina bottae | 16 | 43% |
| 3 | Eastern racer Coluber constrictor | 12 | 10% |
| 4 | Common garter snake Thamnophis sirtalis | 9 | 8% |
| 5 | Gopher snake Pituophis catenifer | 9 | 6% |
When are snakes out in Missoula County?
Observation records of snakes in Missoula County run mostly April through September, peaking in May with 27% of them; across Montana the peak is June.
What spiders are in Missoula County?
In all, 24 spider species are on the Missoula County list. The most recorded are the McCook's split wolf spider (256), the pale thin-legged wolf spider (73) and Gnaphosa muscorum (56). Missoula County holds more than half of all Montana records of the McCook's split wolf spider, the pale thin-legged wolf spider, Gnaphosa muscorum and Pardosa dorsalis.
Related species: Pardosa saxatilisRelated species: Pardosa saxatilis
| # | Species | Records | Share of Montana records |
|---|---|---|---|
| 1 | McCook's split wolf spider Schizocosa mccooki | 256 | 100% |
| 2 | Pale thin-legged wolf spider Pardosa distincta | 73 | 88% |
| 3 | Gnaphosa muscorum | 56 | 98% |
| 4 | Pardosa dorsalis | 50 | 98% |
| 5 | Pardosa wyuta | 28 | 100% |
| 6 | Goldenrod crab spider Misumena vatia | 17 | 28% |
| 7 | Thanatus formicinus | 17 | 74% |
| 8 | California flattened jumping spider Platycryptus californicus | 15 | 100% |
| 9 | Zebra spider Salticus scenicus | 15 | 28% |
| 10 | Spinyrib wolf spider Alopecosa aculeata | 13 | 59% |
| 11 | Cat-faced spider Araneus gemmoides | 10 | 71% |
| 12 | Cone-shaped orbweaver Cyclosa conica | 9 | 60% |
| 13 | Western lynx spider Oxyopes scalaris | 9 | 82% |
| 14 | Barn funnel weaver Tegenaria domestica | 8 | 89% |
| 15 | Banded garden spider Argiope trifasciata | 7 | 16% |
| 16 | Filmy dome spider Neriene radiata | 7 | 47% |
| 17 | Forest wolf spider Hogna frondicola | 7 | 64% |
| 18 | Hobo spider Eratigena agrestis | 5 | 62% |
| 19 | Bronze jumper Eris militaris | 3 | 33% |
| 20 | Western black widow venomous Latrodectus hesperus | 3 | 33% |
| 21 | Johnson jumper Phidippus johnsoni | 2 | 17% |
| 22 | Fierce orbweaver Araneus saevus | 1 | 20% |
| 23 | Sixspotted orbweaver Araniella displicata | 1 | 12% |
| 24 | Utah crab spider Bassaniana utahensis | 1 | 50% |
When are spiders out in Missoula County?
Observation records of spiders in Missoula County run mostly April through October, peaking in June with 20% of them; across Montana the peak is July.
What stands out in Missoula County
Species for which Missoula County holds a large share of all Montana records: Pardosa wyuta, 100% (28 of 28); the McCook's split wolf spider, 100% (256 of 257); Gnaphosa muscorum, 98% (56 of 57); Pardosa dorsalis, 98% (50 of 51); the pale thin-legged wolf spider, 88% (73 of 83); Thanatus formicinus, 74% (17 of 23); the spinyrib wolf spider, 59% (13 of 22); the northern rubber boa, 43% (16 of 37).
Common in Montana, not on the Missoula County list
Among the snakes most recorded across Montana, these do not reach the county list: the prairie rattlesnake (344 statewide), the plains garter snake (45 statewide), the plains hog-nosed snake (19 statewide) and the central plains milksnake (12 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 Montana, these do not reach the county list: Clubiona mixta (22 statewide) and the turf running spider (21 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Missoula County
No rattlesnakes reach the county list, but the prairie rattlesnake is on the Montana list: treat any snake like it as venomous until identified. Harmless species often taken for them here: the gopher snake. No recluse spiders reach the county list, and GBIF holds no recluse spider record for Montana under any license, so one reported here is most likely a harmless lookalike: the hobo spider.
Missoula County among Montana counties
By licensed snake records Missoula County ranks 5th of 49 Montana counties with any.
The whole state: venomous species in Montana, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.