Venomous snakes in Colorado

Venomous snakes living in Colorado

3species, plus 1 with rare records

Western rattlesnake, Prairie rattlesnake, Western massasauga. A bite from any of these is a medical emergency.

How to recognize them

• Western rattlesnakeDangerous85 records, 10 counties
• Prairie rattlesnakeDangerous1,948 records, 43 counties
• Western massasaugaMedically significant40 records, 5 counties

Western rattlesnake Crotalus oreganus

• Brown, gray or olive with darker blotches down the back
• Blotches turn to bands toward the rattle
• Pale line from behind the eye to the jaw

Prairie rattlesnake Crotalus viridis

• Greenish gray to brown with dark blotches down the back
• Blotches narrow into bands near the tail
• Two pale lines on the side of the face

Western massasauga Sistrurus tergeminus

• Pale gray with dark brown blotches down the back
• Small rattle
• Nine large plates on top of the head

Every venomous snake species known from the US is on this site.

Counties with records

Active months

Rare records

• Rare records Cottonmouth 1 open record

Harmless snakes people mistake for them

• Rattlesnake vs Gopher Snake Gopher snake: harmless

• Water snakeHarmlessHarmless
• Northern water snakeHarmlessHarmless
• Milk snakeHarmlessHarmless
• Gopher snakeHarmlessHarmless

Quick answers

• Lives here Are there rattlesnakes in Colorado?
• Not here Are there copperheads in Colorado?
• Rare records Are there cottonmouths in Colorado?
• Not here Are there coral snakes in Colorado?

More for Colorado

• All venomous animals in Colorado
• Venomous spiders in Colorado
• Scorpions in Colorado
• Centipedes in Colorado

Venomous snakes in neighboring states

• Kansas
• Nebraska
• New Mexico
• Oklahoma
• Utah
• Wyoming