Colorado
Snakes in Larimer County
11 species have been documented here, 1 of them venomous.
Venomous snakes in Larimer 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 Larimer County

Western Terrestrial Garter Snake
Thamnophis elegans
Harmless

Gopher Snake
Pituophis catenifer
Harmless

Plains Garter Snake
Thamnophis radix
Harmless

Prairie Rattlesnake
Crotalus viridis
Venomous

North American Racer
Coluber constrictor
Harmless

Common Garter Snake
Thamnophis sirtalis
Harmless

Common Watersnake
Nerodia sipedon
Harmless

Western Milksnake
Lampropeltis gentilis
Harmless

Eastern Milksnake
Lampropeltis triangulum
Harmless

Plains Black-headed Snake
Tantilla nigriceps
Harmless

Lined Snake
Tropidoclonion lineatum
Harmless
Compiled from verified GBIF & iNaturalist observations. Informational only.
Snakes in Larimer County: FAQ
- Are there venomous snakes in Larimer County, Colorado?
- Yes. 1 venomous snake species has verified records in Larimer County, Colorado, including Prairie Rattlesnake. Most snakes in Larimer County, Colorado, however, are harmless.
- How many snake species live in Larimer County, Colorado?
- 11 snake species have verified records in Larimer County, Colorado, of which 1 is venomous.
- What is the most commonly seen snake in Larimer County, Colorado?
- The Western Terrestrial Garter Snake is the most frequently reported snake in Larimer County, Colorado, based on verified wildlife observations.
- What should I do if I see a venomous snake in Larimer 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.