Snakes in Colorado

At a glance

15 of the 63 snakes on Learn2ID live in Colorado, part of the Mountain West. 3 are venomous: Prairie Rattlesnake, Western Massasauga and Western Rattlesnake. Common Gartersnake, Ring-necked Snake, Terrestrial Gartersnake and Western Hog-nosed Snake have only a mild venom. The biggest group here is kingsnakes & milksnakes: 3 of the 15. 5 look-alike pairs here involve a venomous snake — see “Commonly confused” below.