Venomous snakes are found on every continent except for Antarctica. Worldwide, there are roughly 600 different species of venomous snakes coming in all sizes, colors and patterns, each one a little different than the next. Many of the world’s venomous snakes occur in places along the equator or the tropics where the climate is great for hosting all sorts of reptiles. That being said, the United States is home to a fairly long list of venomous snakes. Venomous snakes can be found in nearly every state in the country; however, some states are home to more species than others. In this article, we’ll go over the types of venomous snakes in the US that you may encounter.
Venomous snakes in the United States
There are 22 species and 37 subspecies of venomous snakes in the United States. The number of species and subspecies can change over time as scientists learn more information about species. These species can be placed into 4 groups: copperheads, cottonmouths, rattlesnakes, and coral snakes.
1. Western Diamondback Rattlesnake (Crotalus atrox)
The Western Diamondback Rattlesnake is an abundant species of Rattlesnake in the southwest United States. They typically grow to be anywhere between 4-6 feet with adult males growing larger than adult females. These snakes are thought to be responsible for the most venomous snake bites in the United States.
2. Eastern Diamondback Rattlesnake (Crotalus adamanteus)
The Eastern Diamondback Rattlesnake is the largest species of Rattlesnake and actually one of the largest venomous snakes in the world (Wildlife Informer | Largest Venomous Snakes in the World). Eastern Diamondbacks can get up to nearly 8 feet long, however the average Eastern Diamondback is between 5-6 feet.
3. Sidewinder (Crotalus cerastes)
The Sidewinder gets its common name from the way it moves. Sidewinders move their coils (you guessed it!) sideways which allows them to get traction on desert sand. This type of movement allows for them to move incredibly quick, up to 18 mph! On average, they are between 19.5-31.5 inches. There are 3 known subspecies:
- Mojave Desert Sidewinder (Crotalus cerastes cerastes)
- Sonoran Desert Sidewinder (Crotalus cerastes cercobombus)
- Colorado Desert Sidewinder (Crotalus cerastes laterorepens)
4. Mojave Rattlesnake (Crotalus scutulatus)
The Mojave Rattlesnake has one of the most potent venoms of any rattlesnake. Their venom affects the nervous system and attacks the blood stream, making this a snake you definitely wouldn’t want to be bitten by! Mojave Rattlesnakes on average grow to be 3.3 feet long. There is one subspecies that is also found in the United States that shares the same common name.
- Mojave Rattlesnake (Crotalus scutulatus scutulatus)
5. Santa Catalina Rattlesnake (Crotalus catalinensis)
The Santa Catalina Rattlesnake only occurs on Isla Santa Catalina off the coast of Southern California. What’s interesting about this “rattlesnake” is that it lacks a rattle like the rest of the snakes found in this group. Santa Catalina Rattlesnakes grow to be up to 28 inches long and are classed as critically endangered. Due to this, I was unable to find a picture I was allowed to use.. but if you want to see one a simple image search in Google will show several results.
6. Timber Rattlesnake (Crotalus horridus)
The Timber Rattlesnake is the species of Rattlesnake that can be found the furthest North in the United States. As suggested by the name, these Rattlesnakes can be found in forested areas within rugged terrain. They grow to quite large and on average are 3-5 feet long.
7. Rock Rattlesnake (Crotalus lepidus)
The Rock Rattlesnake is a small species, growing only as long as 32 inches. Rock Rattlesnakes are likely named after their habitat preference of areas with many rocks and or limestone. They are lightly colored which helps them to blend into their environment. There are two subspecies found in the US:
- Banded Rock Rattlesnake (Crotalus lepidus klauberi)
- Mottled Rock Rattlesnake (Crotalus lepidus lepidus)
8. Speckled Rattlesnake (Crotalus mitchellii)
The Speckled Rattlesnake is endemic to the Southwestern United States as well as Northern Mexico. This species was actually named after a doctor (Silas Mitchell) that dedicated his work to studying rattlesnake venom. These snakes on average grow to be around 39 inches long. There are three subspecies found in the US:
- Southwestern Speckled Rattlesnake (Crotalus mitchelli phyrrhus)
- San Lucan Speckled Rattlesnake (Crotalus mitchelli mitchelli)
- Panamint Rattlesnake (Crotalus mitchelli stephensi)
9. Black-tailed Rattlesnake (Crotalus molossus)
The Black-tailed Rattlesnake can be found in the Southwestern United States and typically inhabits grasslands, forests, desert areas and in the mountains. They are actually considered to be some of the more docile Rattlesnakes and bites from this species are incredibly rare. They are typically 30-42 inches with females growing larger than males. There is one subspecies also found in the US:
- Northern Black-tailed Rattlesnake (Crotalus molossus molossus)
10. Pacific Rattlesnake (Crotalus oreganus)
The Pacific Rattlesnake is widely distributed throughout the Northwest and can be found as far North as British Columbia, Canada. Throughout their life, Pacific Rattlesnakes will change in appearance with very distinct patterns when they are juveniles that fade with age. On average, they are around 40 inches long. There are 7 subspecies found in the US:
- Grand Canyon Rattlesnake (Crotalus oreganus abyssus)
- Coronado Island Rattlesnake (Crotalus oreganus caliginis)
- Arizona Black Rattlesnake (Crotalus oreganus cerberus)
- Yellow Rattlesnake (Crotalus oreganus concolor)
- Southern Pacific Rattlesnake (Crotalus oreganus helleri)
- Great Basin Rattlesnake (Crotalus oreganus lutosus)
- Northern Pacific Rattlesnake (Crotalus oreganus oreganus)
11. Twin-Spotted Rattlesnake (Crotalus pricei)
The Twin-Spotted Rattlesnake is one of the smaller Rattlesnake species found on this list, growing on average to be around 20-24 inches. Their range is fairly limited, and they can only be found in a few different areas in Southern Arizona. There is one subspecies also found in the US:
- Western Twin-Spotted Rattlesnake (Crotalus pricei pricei)
12. Red Diamond Rattlesnake (Crotalus ruber)
The Red Diamond Rattlesnake is a fairly large Rattlesnake and on average is between 40-55 inches. They are found along the Baja Peninsula in Southern California and prefer a cooler coastal climate but can also be found in desert areas and in the mountains. There is one subspecies found in the US sharing the same common name:
- Red Diamond Rattlesnake (Crotalus ruber ruber)
13. Tiger Rattlesnake (Crotalus tigris)
Tiger Rattlesnakes are highly venomous Rattlesnakes. They are small, growing to be an average of 24 inches, but their venom can pack a mean punch. Unlike many Rattlesnake species, these snakes are not only found at ground level and have been known to be found in bushes and shrubs as well as in the water.
14. Prairie Rattlesnake (Crotalus viridis)
Prairie Rattlesnakes are widely distributed throughout the United States and can be found in the Great Plains, as south as Northern Mexico and as far North as Southern Canada. Because they have such a wide distribution, they have a very diverse diet and eat anything from mammals, birds, reptiles and amphibians. They are typically around 3.3 feet long. There are two subspecies found in the US:
- Hopi Rattlesnake (Crotalus viridis nuntius)
- Prairie Rattlesnake (Crotalus viridis viridis)
15. Ridge-nosed Rattlesnake (Crotalus willardi)
The Ridge-nosed Rattlesnake is the official state reptile of Arizona despite it being found only in a few locations in Southern Arizona and New Mexico. They are smaller growing up to 2 feet long and are considered to be very reclusive. They can be very difficult to find as they are only in wooded mountain ranges. There are two subspecies found in the US:
- New Mexican Ridge-nosed Rattlesnake (Crotalus willardi obscurus)
- Arizona Ridge-nosed Rattlesnake (Crotalus willardi willardi)
16. Massasauga Rattlesnake (Sistrurus catenatus)
Massasauga Rattlesnakes are widely distributed through the United States from Arizona to New York. It is not so picky about its habitat and can be found in swamps, grasslands, and wetlands. They are typically between 24-30 inches long. Massasauga Rattlesnakes are listed as “Least Concern” by the IUCN but have declining populations in parts of their range. There are three subspecies found in the US:
- Eastern Massasauga (Sistrurus catenatus catenatus)
- Desert Massasauga (Sistrurus catenatus edwardsii)
- Western Massasauga (Sistrurus catenatus tergeminus)
17. Pygmy Rattlesnake (Sistrurus miliarius)
As you could probably guess from the name, Pygmy Rattlesnakes are a small species, which on average grow to be 16-24 inches. They can be found in the Southeastern United States where they will often use Gopher Tortoise Burrows for shelter. Their venom is not nearly as toxic as some of their relatives. You may also see this species spelled as “Pigmy Rattlesnake”.
There are three subspecies found in the US:
- Dusky Pygmy Rattlesnake (Sistrurus miliarius barbouri)
- Carolina Pygmy Rattlesnake (Sistrurus miliarius miliarius)
- Western Pygmy Rattlesnake (Sistrurus miliarius streckeri)
18. Cottonmouth/ Water Moccasin (Agkistrodon piscivorous)
Like Rattlesnakes, Cottonmouths are pit vipers that have specialized organs to help them detect changes in temperature that they use to catch their prey. Cottonmouths are very common in the Southeastern United States and are found around bodies of water. On average they grow to be 31 inches. There are three subspecies found in the US:
- Florida Cottonmouth (Agkistrodon piscivorous conanti)
- Western Cottonmouth (Agkistrodon piscivorous leucostoma)
- Eastern Cottonmouth (Agkistrodon piscivorous piscivorous)
19. Eastern Copperhead (Agkistrodon contortrix)
Copperheads are in the same genus as Cottonmouths and share many similarities, but people typically separate them, maybe due to the fact that Cottonmouths and Copperheads are associated with different habitat types. Copperheads seem to prefer forested areas and reach lengths up to 20-37 inches. There are five subspecies of Copperheads in the US:
- Northern Copperhead (Agkistrodon contortrix mokasen)
- Southern Copperhead (Agkistrodon contortrix contortrix)
- Broad Banded Copperhead (Agkistrodon contortrix laticinctus)
- Trans-Pecos Copperhead (Agkistrodon contortrix pictigaster)
- Osage Copperhead (Agkistrodon contortrix phaeogaster)
20. Eastern Coral Snake (Micrurus fulvius)
Coral snakes are in the Elapidae family, which also includes snakes like kraits, cobras, king cobras. They have incredibly potent venom which can be deadly. The Eastern Coral Snake is typically around 30 inches. They have very distinct black, red, and yellow bands along their body.
21. Texas Coral Snake (Micrurus tener)
Texas Coral Snakes look very similar to Eastern Coral Snakes and were once considered to be a subspecies of the Eastern Coral Snake. On average, Texas Coral Snakes are a bit smaller than their relatives and grow to be 24 inches.
22. Sonoran Coral Snake (Micruruoides euryxanthus)
The Sonoran Coral Snake can be found in the Southwestern United States. They are very secretive and spend much of their time underground but will come out at night to hunt. Sonoran Coral Snakes grow to be anywhere between 11-24 inches long.
Want to learn more about U.S. venomous snakes? Check out this article out where we show the venomous snakes found in each state.