Colorado
Snakes in Jefferson County
13 species have been documented here, 1 of them venomous.
Venomous snakes in Jefferson 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.
Every snake recorded in Jefferson County
Western Terrestrial Garter Snake
Thamnophis elegans
Harmless
Gopher Snake
Pituophis catenifer
Harmless
Prairie Rattlesnake
Crotalus viridis
Venomous
North American Racer
Coluber constrictor
Harmless
Plains Garter Snake
Thamnophis radix
Harmless
Western Milksnake
Lampropeltis gentilis
Harmless
Common Watersnake
Nerodia sipedon
Harmless
Smooth Greensnake
Opheodrys vernalis
Harmless
Common Garter Snake
Thamnophis sirtalis
Harmless
Lined Snake
Tropidoclonion lineatum
Harmless
Plains Hognose Snake
Heterodon nasicus
Harmless
Plains Black-headed Snake
Tantilla nigriceps
Harmless
Eastern Milksnake
Lampropeltis triangulum
Harmless
Compiled from verified GBIF & iNaturalist observations. Informational only.
Snakes in Jefferson County: FAQ
- Are there venomous snakes in Jefferson County, Colorado?
- Yes. 1 venomous snake species has verified records in Jefferson County, Colorado, including Prairie Rattlesnake. Most snakes in Jefferson County, Colorado, however, are harmless.
- How many snake species live in Jefferson County, Colorado?
- 10+ snake species have verified records in Jefferson County, Colorado, of which 1 is venomous.
- What is the most commonly seen snake in Jefferson County, Colorado?
- The Western Terrestrial Garter Snake is the most frequently reported snake in Jefferson County, Colorado, based on verified wildlife observations.
- What should I do if I see a venomous snake in Jefferson County, Colorado?
- Keep your distance and do not try to catch or kill it. Most bites happen when people handle or corner a snake. If someone is bitten, contact local emergency services or poison control immediately.