The 9 Types of Venomous Snakes in Oklahoma! (ID Guide)
“What kinds of venomous snakes can you find in Oklahoma?”
This question is extremely common. Everyone wants to know if any dangerous snakes live near them and what they look like!
Believe it or not, you can find NINE types of venomous snakes in Oklahoma. But please don’t live in fear, thinking that you are going to be bitten. In general, snakes try to avoid any contact or interaction with people. As long as you leave them alone, you shouldn’t have any trouble!
Did you know that snakes are considered venomous, NOT poisonous? If you eat something that makes you sick, then it’s considered “poisonous.” If an animal, like a snake, delivers its toxins when it bites, then it’s considered “venomous.”
*If you come across any of these species, PLEASE DO NOT DISTURB! Venomous snakes are dangerous animals and should be left alone. The more you agitate them, the more likely you could get bitten. DO NOT RELY ON THIS ARTICLE to correctly identify a snake that has recently bitten you. If you have recently been bitten, GO DIRECTLY to the nearest hospital to get help and to determine if the snake is venomous.*
9 Venomous Snakes That Live in Oklahoma:
RELATED: The 33 Types of SNAKES Found in Oklahoma! (ID Guide)
#1. Eastern Copperhead
- Agkistrodon contortrix
- Adults reach lengths between 20 and 37 inches.
- Stout body and broad head and elliptical pupils.
- Coloration varies from pale tan to pinkish-tan with darker, splotchy, hourglass-shaped bands, which are darker at the edges and thinner towards the center of the back.
Look for these venomous snakes in eastern Oklahoma in deciduous forests and mixed woodlands, often near rocky outcroppings. However, they may also be seen in swampy areas, coniferous forests, and near river habitats. You’re most likely to see them active during the day in the spring and fall when the weather is cooler. During the middle of summer, Eastern Copperheads are often nocturnal. The range of the Eastern Copperhead overlaps with its cousin, the Broad Banded Copperhead, in eastern Oklahoma.
Eastern Copperhead Range Map
Credit: Virginia Herpetological Society
This species is an ambush hunter, meaning that it selects a suitable site and waits to surprise its prey. In addition, copperheads are considered “pit vipers,” which means they have a heat-sensing organ located between their eyes. This adaptation helps these venomous snakes locate and judge the size of their prey by being able to sense infrared!
Bites from these venomous snakes are rarely fatal in Oklahoma.
The venom they produce has relatively low potency. In addition, copperheads also frequently employ false strikes, dry bites, and warning bites. Dry bites contain no venom, and warning bites have a relatively small amount of venom.
These snakes primarily feed on small rodents, frogs, birds, and large insects, such as cicadas. After the initial bite, they will wait for the venom to take effect before consuming their prey whole.
When threatened, Eastern Copperheads use a “freeze” defense. Their excellent camouflage coloration allows them to blend into the leaf litter and soil. However, they may also vibrate their tails in the leaves when approached to produce a buzzing sound. This noise may serve to warn predators, similar to a rattlesnake, or divert a predator’s attack to their tail.
#2. Broad-banded Copperhead
- Agkistrodon laticinctus
- Adults range from 20 to 36 inches in length.
- Tan coloration with wide, dark bands.
- Broad head is distinct from the neck, heat-sensing pits between the eyes and nostrils, and elliptical pupils.
The Broad-banded Copperhead is found in woodland habitats that include oak, cedar, and juniper trees. They prefer areas with heavy leaf litter or pine needles and can sometimes be spotted near rotten logs, piles of woody debris, ledges, and rocky bluffs. Its range overlaps with the Eastern Copperhead in eastern Oklahoma.
Broad-banded Copperhead Range Map
Credit: Virginia Herpetological Society
Like its cousin, the Eastern Copperhead, this species is an ambush hunter. Its superb camouflage allows it to wait and strike unsuspecting prey. The Broad-banded Copperhead is opportunistic and feeds on a wide range of creatures, including rodents, birds, lizards, frogs, and insects.
When threatened, these venomous snakes normally lie motionless, relying on camouflage for defense. This adaptation sometimes leads to unaware humans and pets stepping on them. They may also vibrate their tail in the leaf litter and lift it up as a warning. If they continue to be disturbed, they may deliver false strikes or bite.
Broad-banded Copperheads have a hemotoxic venom that destroys blood cells and tissue. Luckily, bites to humans are uncommon, and the venom is not ordinarily deadly to healthy adults but can cause localized swelling, necrosis, and severe pain. If bitten, medical attention should be sought.
#3. Northern Cottonmouth
- Agkistrodon piscivorus
- Adults range from 26 to 35 inches in length. Females are typically smaller than males.
- Most individuals are dark gray to black with a broad head, heat-sensing pits between the eyes and nostrils, elliptical pupils, and a blunt snout.
- Some individuals have a brown, gray, tan, or blackish coloration.
Cottonmouths are the ONLY aquatic venomous snake in Oklahoma.
Be on the lookout for them near bodies of water, including swamps, marshes, ponds, and slow-moving streams and rivers, as well as semi-permanent water sources like flooded fields and drainage ditches. But they aren’t limited to just aquatic habitats and can also be found in palmetto thickets, pine forests, dune areas, and prairies.
Northern Cottonmouth Range Map
Credit: Virginia Herpetological Society
Since they are typically near water, the bulk of their diet is made up of fish and frogs. But they are opportunistic and will also eat small mammals, birds, turtles, small alligators, and other snakes.
These venomous snakes, which are also commonly called Water Moccasins, Black Moccasins, or Gapers, have several defensive tactics. They often vibrate their tail in the leaf litter, pull their heads up and back, and then open their mouth to hiss and expose a white interior. This particular display is what earned them the name “cottonmouth.”
Luckily, receiving a bite from a Northern Cottonmouth is rare. But when it does happen, it is very serious. Their venom destroys tissue and is more toxic than a copperhead but not as severe as a rattlesnake. It is rare to die from their bite, but it does cause swelling and bruising and can leave scars.
#4. Texas Coral Snake
- Micrurus tener
- Adults typically range from 20-30 inches in length.
- Red and black banding with narrower bands of yellow in between.
- Smooth scales and black-colored specks within red bands.
The Texas Coral Snake was once considered to be a subspecies of the Eastern Coral Snake. Although it looks similar and shares the same coloration, it is slightly longer and thicker than its eastern cousin.
These venomous snakes are rarely seen in Oklahoma.
They are nocturnal and spend most of their time hiding underground or beneath leaf litter or rotting logs. Your best chance to see a Texas Coral Snake is on a warm rainy night when the temperature remains above 78°F.
These venomous snakes are sometimes confused with Scarlet Snakes and Scarlet King Snakes, both of which are entirely harmless. To help distinguish these species, you may use the following rhyme, “Red next to black, safe from attack; red next to yellow, you’re a dead fellow.“
This interesting snake feeds almost exclusively on other snakes, with Thread snakes being their most favorite victims, though skinks may also be consumed. Like other coral snakes, this species is venomous and has a potent neurotoxin that is used to immobilize and kill prey.
#5. Western Diamond-backed Rattlesnake
- Crotalus atrox
- Adults typically grow to about 4 feet in length.
- Coloration ranges from brown, gray, brick red, pinkish, and chalky white. Look for the darker diamond-shaped blotches down its back, which are outlined by white scales.
- Broad, spade-shaped head with a black mask over the eyes. Elliptical pupils and pits between eyes and nostrils.
- A rattle on the tail alternates between black and white-colored bands.
This famous venomous snake has a wide range of habitats in Oklahoma!
You might spot them in grassy plains, forested areas, rocky hillsides, and river bottoms. But your best chance to see one might be on a rural road in the evening because of the heat the pavement retains.
Western Diamond-backed Rattlesnake Range Map
Western Diamond-backed Rattlesnakes hibernate in communal caves, dens, or rock ledges called hibernacula during the winter. They sometimes share these spaces with snakes of other species and can survive in hibernation for several months without eating.
The Western Diamond-backed feeds on small mammals such as squirrels, chipmunks, gophers, prairie dogs, rabbits, mice, and rats. They will also consume birds that fly within reach. Like other pit vipers, they ambush their prey and track them while the venom takes effect.
When threatened, the Western Diamond-backed will typically stand its ground. They rattle and coil, lifting themselves off the ground to prepare to strike.
If you hear their characteristic rattle, make sure to leave the area slowly! Due to their specialized fang and large venom glands, these snakes can deliver a lot of venom in a single bite! Untreated bites have a mortality rate of 10 – 20%, so make sure to get to the hospital quickly if struck!
These venomous snakes reach sexual maturity at three years of age and mate in the spring after emerging from hibernation. Females give birth to ten to twenty live babies. The young snakes have a high mortality rate, but those that survive may live for 20 years or more!
#6. Timber Rattlesnake
- Crotalus horridus
- Adults typically range from 30 to 60 inches in length.
- Coloration is variable, and generally ranges from yellowish brown to gray to almost black. Look for dark brown or black crossbands on their back.
- Heavy-bodied with characteristic rattle on the tail.
The Timber Rattlesnake, which is also known as the Canebrake Rattlesnake, can be found in a wide variety of habitats in eastern Oklahoma. Look for these venomous snakes in lowland thickets, high areas around rivers and flood plains, agricultural areas, deciduous forests, and coniferous forests.
Timber Rattlesnake Range Map
Credit: Virginia Herpetological Society
These venomous snakes are ambush predators, waiting for unsuspecting prey to come within range of their strike. They feed primarily on small mammals but may also consume frogs, birds, and other smaller snakes. Timber Rattlesnakes strike their prey and release them, waiting until the venom has taken effect before eating them.
These venomous snakes are potentially the most dangerous species found in Oklahoma due to their large size, long fangs, and high yield of venom. Luckily, Timber Rattlenskaes have a mild disposition and don’t often bite. They typically give plenty of warning by rattling and posturing.
The Timber Rattlesnake has played an interesting role in U.S. history. As it can be found in the area of the original 13 Colonies, it was used as a symbol during the American Revolution. In 1775 it was featured at the center of the “Gadsden Flag.” This yellow flag depicts a coiled and ready-to-strike Timber Rattlesnake and the words “Don’t Tread on Me.”
#7. Prairie Rattlesnake
- Crotalus viridis
- Adults typically range between 3.3 and 5 feet in length.
- Coloration is highly variable and can be greenish-gray, olive green, greenish-brown, light brown, or yellow. All variations have dark blotches on the body that turn into rings near the tail.
- Broad triangular head, elliptical pupils, heat-sensing pits between the eyes and nostrils, and a tail rattle.
These venomous snakes can be found in western Oklahoma in open prairies, grasslands, semi-desert shrublands, and forested environments. They can even be found at elevations up to 9500 feet!
The Prairie Rattlesnake hibernates during the winter, often in communal dens. These dens are typically rock crevices, caves, or old mammal burrows. Individual snakes will return to the same den each winter and migrate up to seven miles to their hunting grounds in the spring.
When they feel threatened, these snakes will freeze, trying to use their camouflage to avoid detection. They may also quietly crawl away to cover. If approached, they may coil and rattle their tail as a warning before striking. Their potent venom has both hemotoxic and neurotoxic properties, and although rare, can be fatal to an adult human.
Prairie Rattlesnakes are listed on the ICUN Red List as a species of least concern. However, they are considered threatened and declining in parts of their range. They have faced pressure from habitat fragmentation and hunting.
#8. Western Massasauga
- Sistrurus tergeminus
- Adults range from 14 to 36 inches in length.
- Coloration is gray to light brown with dark brown blotches on the back.
- Thick body, large triangular head, heat-sensing pits between the eyes and nostrils, elliptical pupils, and rattle on the tail.
- Often referred to as the Prairie Massasauga.
The Western Massasauga is one of the smallest venomous snakes in the country! They primarily inhabit grassland habitats but can also be found in open sagebrush prairie, rocky hillsides, prairie hillsides, open wetlands, and grassy wetlands.
Western Massasauga Range Map
This venomous snake is secretive and is not often seen in Oklahoma.
When detected, they often freeze rather than rattling. However, when they do rattle, Western Massasaugas make a distinctive sound. Their rattle is significantly higher pitched than larger rattlesnakes and has earned this small snake the nickname “buzz tail.”
Though their venom is highly potent, the small quantity they deliver makes their bites much less likely to cause fatality in humans than some larger venomous snakes. However, you still need to respect them as their venom is hemotoxic and will cause localized swelling, extreme pain, and necrosis. Medical attention should be sought immediately if bitten!
#9. Western Pygmy Rattlesnake
- Sistrurus miliarius streckeri
- Adults are small and range from 1 to 1.5 feet in length.
- Pale gray or brown. Dark spots that are irregular in shape.
- Thick body, dark bands that run from the corners of the eyes to the jaw, a small rattle prone to breaking, and elliptical pupils.
- Western Pygmy Rattlesnakes are subspecies of the Pygmy Rattlesnake (Sistrurus miliarius).
This species is the smallest venomous snake found in Oklahoma!
Western Pygmy Rattlesnakes occupy a wide variety of habitats. Naturally, they can be found in pine forests, dry upland forests, floodplains, sandhills, and near lakes, rivers, and marshes. They are often encountered in urban areas and may be seen in gardens and brush piles.
These venomous snakes are rarely seen in Oklahoma because they are so small and well camouflaged. When they are found, they typically remain silent and motionless and rely on blending into their environment.
It’s rare to hear them rattle. When they do, it sounds more like a faint insect and can be hard to hear unless you’re within a few feet of one.
Due to their small size, a bite typically isn’t fatal to healthy adults and is considered less severe than the bite of most other venomous snakes. But make no mistake, these snakes’ cytotoxic venom can cause pain and necrosis for a few days.
Do you need additional help identifying a venomous snake?
I recommend purchasing a Peterson Field Guide to the Reptiles and Amphibians of North America. These books have lots of helpful information, including pictures and range maps. View Cost - Amazon
Which of these venomous snakes have YOU seen in Oklahoma?
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