Discover 8 Water Snakes Found in Arkansas Waters

Written by Gail Baker Nelson
Updated: June 22, 2023
© Nathan A Shepard/
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Arkansas’ temperate weather and extensive river system make it a perfect home for all snakes, but especially water snakes.

To discover which water snakes inhabit Arkansas’ waters, we turned to and the University of Arkansas to find the most common watersnakes. The Natural State has 36 native snake species and at least a dozen are aquatic. While you’re probably most familiar with venomous cottonmouths and nonvenomous watersnakes. Let’s discover which snakes you’ll encounter in Arkansas waters. 

1. Northern Cottonmouth (Agkistrodon piscivorus)

Western cottonmouth snake isolated
Western cottonmouth snake showing off its white mouth.

©Ryan M. Bolton/

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One of the most feared of all water snakes is the cottonmouth. Also called the water moccasin, it is the only venomous semiaquatic snake in North America.

Highly venomous cottonmouth snakes are common in Arkansas waters. Unless they’re striking at something, these fish and frog eaters are slow-moving on the land — and elegant dancers in the water. They tend to be more buoyant than other semiaquatic snakes and swim across the water with most of their body out of the water. 

Water moccasins have keeled scales and stout bodies that narrow sharply towards the tail. Their pattern as adults is nearly invisible because they darken with age. Young snakes have bright patterns that resemble their closely related cousins, the copperheads. Their light base color varies and can be tan, brown, gray, yellowish-olive, or blackish; they have darker crossbands that narrow towards the center of their backs. However, unlike a copperhead’s smooth pattern edges, a cottonmouth pattern has dark, jagged edges and usually a few darker spots inside each cross band.

Their heads are typical chunky pit viper heads and a dark band that starts right behind their cat-eye style eyes. One of the things that set them apart from other pit vipers is how they hold their heads — with their snouts pointing up. 

Perhaps because of its fearsome reputation, there are a few myths surrounding its behavior — here are two myths dispelled.

Myth 1: Cottonmouths chase you.

No. You are at least 100 pounds bigger than that snake. The only thing it wants to do is get away from you. If it thinks its best shot is to get past you to the water or its current shelter, that’s what it will do.

However, the myth probably started because they don’t back down and slither off like other snakes do when they’re scared. Instead, they coil up and show off their cotton-white mouth by throwing it open.

Myth 2: Cottonmouths can’t bite underwater.

They eat fish. No self-respecting fish will jump onto shore and beg to be eaten. Cottonmouths hunt underwater. They bite and then release the animal, allowing its venom to do its job.

So, yes, they can bite underwater. Yes, if you step on one underwater, it will probably envenomate you. We’re not sure where that myth got started, but we’re trying to set the story straight.

2. Mud Snake (Farancia abacura)

mud snake, Farancia abacura
Mud snakes are almost completely aquatic and only leave the water to lay eggs, brumate, and escape a drying waterway.


Mudsnakes only live in the southeastern half of Arkansas. They’re nocturnal and only leave the water to lay eggs, brumate, and find a moist place to survive droughts.

This species grows up to four and a half feet long and has a thick, cylindrical body. Its smooth, glossy scales are black on the dorsal side with a red belly. Some snakes don’t have red; instead, they have white where it would otherwise appear. In addition, they have a sharp point at the end of their tail that they use to poke at their prey, which gives them the nickname “Stinging Snake.” However, it’s not a stinger; these snakes are completely harmless.

The mud snake mainly feeds on giant salamanders and lives wherever it can find prey in fresh or brackish water.

3. Eastern Garter Snake (Thamnophis sirtalis sirtalis)

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Common eastern Garter snake, coiled in the grass. Garter snakes are harmless to people, but have mildly venomous saliva.

©K Quinn Ferris/

Of all the North American snakes, garter snakes are the most widespread. They inhabit areas as far north as Canada and handle the cold better than most New World snakes. In Arkansas, they’re everywhere.

Eastern garter snakes are long and thin, averaging two to four feet long. In Arkansas, most of the eastern garter snakes have dark bodies with orange or yellow stripes down the length of their bodies. 

These harmless snakes have mildly venomous saliva that only affects their prey, typically small amphibians, and worms. They also eat small mice and anything else they can overpower.

Features common to Nerodia watersnakes:

Arkansas is home to five water snakes in the Nerodia genus. It makes the “Natural State” home to half of all North American water snakes. These snakes, like the cottonmouth, are semiaquatic and spend much time hunting in the water. However, they have a few things in common, which we’re listing here.

  • Eyes set higher on the head with round pupils. You can see their eyes when you look from the top down.
  • Vertical labial bars. These are vertical lines along the lips.
  • Nonvenomous. They are harmless to you.
  • Crazy sharp teeth. They need these teeth to capture fish while underwater.
  • Semiaquatic. Water snakes spend hours in the water every day.
  • Keeled scales. They look rough to the touch.
  • Fish and amphibian eaters. Although they’ll eat other things, these are their favorite foods.
  • Give birth, don’t lay eggs. True for all natricine snakes.

4. Common Watersnake (Nerodia sipedon)

Nerodia sipedon
Common watersnakes are also called northern watersnakes and are common across the eastern United States.


Also called banded water snakes, brown water snakes, and black water adders, these snakes are more common in northwestern Arkansas. 

They typically measure two to three feet long but can grow to four feet and weigh up to a pound. Like many water snakes, common watersnakes undergo an ontogenic (age-related) change. These snakes begin life with strong patterns that fade with age. Young common water snakes are gray or brown to brownish-black with dark crossbands that become blotches further down the body. 

These snakes eat a little of anything they find in the water: fish, tadpoles, frogs, worms, leeches, large insects, and crayfish. They’re often spotted basking on rocks and stumps, usually taking off when they spot you.

5. Plain-Bellied Watersnake (Nerodia erythrogaster)

Nerodia erythrogaster - Plain-bellied watersnake
Young plain-bellied watersnakes have brighter patterns than adult snakes.

©Tyler Albertson/

Common throughout Arkansas, the only area plain-bellied watersnakes don’t inhabit is a small chunk of north-central Arkansas.

This big and thick-bodied species leads to more confusing misidentifications with cottonmouths. Plain-bellied watersnakes also turn dark as they age, going from brown or greenish gray with darker blotches to solid black, green, olive green, or gray with a solid-colored belly. Adults measure about two to four feet long.

Plain-bellied watersnakes spend more time on the land than other watersnakes and often travel up to 100 yards away from water. As a result, they eat a lot of amphibians, including frogs, toads, and salamanders.

6. Banded Watersnake (Nerodia fasciata)

banded watersnake on the ground
Banded watersnakes have several subspecies, found in waterways throughout their range.

©Deborah Ferrin/

These snakes are more common in the southeastern half of Arkansas, where they’re seen basking on logs and branches. 

The banded watersnakes usually grow between two and four feet long with stocky bodies. Some sources consider them a plain-bellied watersnake subspecies. They have a light base color with darker crossbands, and their color varies and can be gray, greenish-gray, or brown. They, too, become darker as they age, becoming almost black. 

This species eats fish and frogs but sometimes preys on birds, crayfish, and snakes.

7. Diamondback Watersnake (Nerodia rhombifer)

Diamondback Water Snake
Diamondback watersnakes eat more frogs, toads, and salamanders than other watersnakes.

©Laurie L. Snidow/

Reasonably common across Arkansas, diamondback watersnakes are common where they have enough food and water. They’re often mistaken for rattlesnakes on land and cottonmouths in the water. However, these nonvenomous snakes are harmless.

They’re usually brown, dark brown, or olive green with black markings. Diamondback water snakes’ pattern looks roughly diamond-shaped, which many people describe as looking like a chainlink fence. These snakes average between two and a half and four feet long but can grow to six feet. Diamondback watersnakes have broad flat heads that can spread out even further to make them look bigger. 

This species hangs from branches overhanging the water while they watch and wait for fish or prey to swim close enough.

8. Mississippi Green Watersnake (Nerodia cyclopion)

Mississippi Green Water Snake
This snake lives in marshes and swamps, mostly along the gulf coast in Louisiana and Texas, but also north into Arkansas.

©Ryan M. Bolton/

These snakes only have a small strip of range in eastern Arkansas; most Mississippi green watersnakes occur along the gulf coast in Louisiana and Texas. They prefer marshy, swampy areas and aren’t often found away from water.

Heavy-bodied with keeled scales, Mississippi watersnakes grow between two and four feet long. Unlike other watersnakes, they have one or more extra scales under their eyes. This species is primarily green or brown; its belly is yellowish in the first third, and the rest is dark brown or black with yellow or white half circles. 

Their favorite prey is fish and amphibians, which they hunt by day and night during the warmer seasons.

Other Watersnakes in Arkansas

There are more snakes in and around Arkansas waterways — even though most aren’t water snakes, all snakes can swim. Here are a few more semiaquatic snakes you may encounter in and around the water.

  • Graham’s crayfish snake (Regina grahamii)Queen snake (Regina septemvittata)
  • Glossy swamp snake (Liodytes rigida)
  • Western ribbon snake (Thamnophis proximus)
  • Plains garter snake (Thamnophis radix)
  • Ring-necked snake (Diadophis punctatus)
  • Dekay’s brownsnake (Storeria dekayii)
  • Red-bellied snake (Storeria occipitomaculata)

Summary of 8 Water Snakes Found in Arkansas Waters

#Water SnakeFun Fact
1Northern CottonmouthAlso called the water moccasin – only venomous semiaquatic snake in North America
2Mud SnakeNocturnal, only leaves the water to lay eggs or brumate
3Eastern Garter SnakeHave mildly venomous saliva that only affects their prey
4Common Watersnake Are often spotted basking on rocks and stumps
5Plain-Bellied WatersnakeSpend more time out of the water than other water snakes
6Banded WatersnakeBecome almost black as they age
7Diamondback WatersnakeHangs from branches over water to watch for prey
8Mississippi Green WatersnakePrefers marshy, swampy areas

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About the Author

Gail’s love for a very misunderstood group of animals, reptiles, led her to write about and draw them. She loves the natural world and it’s endless inspiration for her work. She is a freelance writer and illustrator, and her latest book, “Pebble Skins and Fast Walkers: What’s In a Name?” Is due out in early 2023.

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