Snakes

Prairie Rattlesnake

Crotalus viridis

Across the regions where it's common, the Prairie Rattlesnake peaks from May to October.

Shows up in 8 ecoregions and 11 states · venomous

Keep Herp Calendar free

Hi, I'm Nick. I built Herp Calendar on my own and I keep it free, with no ads. If it has helped you find a herp this season, a small tip goes straight into the hosting and the data work. Only if you can spare it. Either way, I'm glad you're here.

Leave a tip

Snakes

Prairie Rattlesnake

Crotalus viridis

venomous

Venomous. Do not handle. Give it room and let it move on. If you're bitten, call 911 or go to an emergency room. Don't cut, suck or ice the bite.

Look, don't take. Many states regulate collecting reptiles and amphibians. Photograph it, log it on iNaturalist and leave it where you found it.

Description

The prairie rattlesnake or Great Plains rattlesnake (Crotalus viridis) is a venomous pit viper species native to the western United States, southwestern Canada, and northern Mexico. This species commonly grows to more than 100 cm (3.3 ft) in length.Wikipedia ↗

Habitat

Prairie rattlesnakes are found in North America over much of the Great Plains, the eastern foothills and some intermontane valleys of the Rocky Mountains, and from southwestern Canada through the United States to northern Mexico. Wright and Wright (1957) and Klauber (1997) both mention Utah as within the range of this species, including maps showing it confined to the extreme southeastern part of the state.Wikipedia ↗

When it's active

Males may compete for females during the breeding season, but western rattlesnake females may not necessarily breed every year. Prairie rattlesnakes have a mating season of about 7 weeks between July-September.Wikipedia ↗Animal Diversity Web ↗

Prairie Rattlesnake — Lon Brehmer · CC BY 4.0

iNaturalist ↗

Harmless look-alikes

Gopher Snake, Pine Snake, Eastern Hognose Snake, Plains Hognose Snake, Mexican Hognose Snake, Prairie Kingsnake, Desert Nightsnake, Chihuahuan NightsnakeSuperficially, gopher snakes resemble many species of rattlesnakes and are often mistaken for them. Animal Diversity Web ↗Non-human predators are likely to be discouraged from attacking gopher snakes when they are mimicing rattlesnakes. Animal Diversity Web ↗Rattlesnakes vs. gopher snakes, bullsnakes and hognose snakes →

When and where it's active

Each row is its own calendar, counted from records in that area. Seasons shift by place.

PeakShoulderQuiet

Ecoregions

JanFebMarAprMayJunJulAugSepOctNovDec

High Plains Southwestern Tablelands Southern Rockies Colorado Plateau Northern Great Plains Chihuahuan Desert Middle Rockies and Wyoming Basin Arizona and New Mexico Mountains

States

JanFebMarAprMayJunJulAugSepOctNovDec

Arizona Colorado Kansas Montana Nebraska New Mexico North Dakota Oklahoma South Dakota Texas Wyoming

About the Prairie Rattlesnake

When is the Prairie Rattlesnake most active?

Across the regions where it's common, the Prairie Rattlesnake peaks from May to October.

Where does the Prairie Rattlesnake live?

It has enough records to show in 8 ecoregions and 11 states, including Arizona, Colorado, Kansas, and Montana.

Is the Prairie Rattlesnake venomous?

Yes. The Prairie Rattlesnake is venomous. Don't handle it, and give it room.

What snakes get mistaken for the Prairie Rattlesnake?

Harmless lookalikes include the Gopher Snake, Pine Snake, and Eastern Hognose Snake.