Wildlife Informer is reader-supported. When you click and buy we may earn an affiliate commission at no cost to you. Learn more.

Water Snakes in Missouri (8 Species With Pictures)

With its many bodies of water like the Lake of the Ozarks, the Mississippi River, and the Missouri River, Missouri makes a comfortable home for many different species of water-dwelling or semi-aquatic creatures, including snakes. Even though all snakes can swim, many live on land most of the time. So in this article we’re going to look particularly at the water snakes in Missouri.

We’ll show you a picture for each one to help identify it in the wild, as well as give you some facts and helpful info about each species. We’ll also tell you if the snake is venomous or not.

We hope you find this list of Missouri water snakes helpful!

Photo collage of water snakes in Missouri



1. Northern Water Snake

Northern Water Snake | Shenandoah National Park
  • Scientific name: Nerodia sipedon
  • Length: 24 – 54 in
  • Venomous: No

The northern water snake, also known as the common water snake lives in habitats near any body of water like lakes, rivers, streams, and ponds. Here they find an abundance of food such as fish, frogs, salamanders, and other amphibians. They are often mistaken for cottonmouths even though they are non-venomous and harmless.

The northern water snake is found throughout much of the central and eastern United States. It’s also the most common water snake in Missouri, found throughout the entire state.  Although, they don’t have much of a population in the very southeastern part of the state, near the Tennessee and Kentucky border.

2. Diamondback Water Snake

Diamondback Water Snake | k.draper | Flickr | CC BY-ND 2.0
  • Scientific name: Nerodia rhombifer
  • Length: 30 – 63 in
  • Venomous: No

Diamondback water snakes are some of the largest water snakes in Missouri with some adults reaching over 5 ft in length. They get their name from the diamond pattern on their backs. They are mostly dark in color and some may have a yellow belly.

The diamondback water snake is common in much of the Southeastern United States. According to this diamondback water snake range map, they are mainly found in Eastern, Western, and parts of Northern Missouri. Diamondback Water Snakes seem to be less common in Central Missouri, so you won’t find these in the Ozarks. 

Diamondback Water Snake | pondhawk | Flickr | CC BY 2.0

These snakes are found near slow moving rivers and streams, swamps, lakes, and ponds. Like the northern water snake, diamondback water snakes feed on aquatic life here such as fish and amphibians.

3. Plain-bellied Water Snake

Yellow-bellied Water Snake | Peter Paplanus | Flickr | CC BY 2.0
  • Scientific name: Nerodia erythrogaster
  • Length: 30 – 48 in
  • Venomous: No

Also known as the yellow-bellied water snake, the plain-bellied water snake is common in Southeastern Missouri and Western Missouri. Though the blotched water snake, a subspecies of the plain-bellied water snake, is found in the western parts of the state.

The plain-bellied water snake is gray, greenish gray, or brownish black on top and yellow or orangish-yellow on bottom. They have little to no pattern. These snakes are also non-venomous, live near bodies of water, and feed on fish and amphibians.

Did you know that water snakes give live birth?
You may also like this article: How do snakes give birth?

4. Broad-banded Water Snake

Broad-banded Water Snake | Melissa McMasters | Flickr | CC BY 2.0
  • Scientific name: Nerodia fasciata confluens
  • Length: 22 – 36 in
  • Venomous: No
You may also like:  3 Species of Invasive Water Snakes in California¬†

One of three recognized subspecies of the southern water snake, Nerodia fasciata, the broad-banded water snake is limited to the southeast corner of Missouri according to this range map.

They are one of the smaller water snakes in Missouri, only reaching about 2 or 3 feet in length. The large, irregular-shaped bands on their back are typically reddish-brown or black separated by gray or yellow making them quite unique. Though unfortunately like other water snakes they are still commonly mistaken for water moccasins and needlessly killed.

They are non-venomous, though like other water snakes broad-banded water snakes can emit a strong smelling musk from the base of their tail. They will also defend themselves fiercely if they feel threatened by you.

5. Graham’s Crayfish Snake

Graham’s Crayfish Snake | photo: Brett_Hondow / Pixabay
  • Scientific name: Regina grahamii
  • Length: 18 – 28 in
  • Venomous: No

Graham’s Crayfish Snakes are the smallest water snakes in Missouri with some adult snakes only reaching about a foot and a half. They get their name because not only are freshly molted crayfish their favorite food, but they also live in and spend their winters in abandoned crayfish burrows.

They’re typically brown or yellowish-brown in color and are found in most of Missouri, except for parts of Central Missouri and the Ozarks.

6. Mississippi Green Water Snake

Mississippi Green Water Snake | Greg Schechter | Flickr | CC BY 2.0
  • Scientific name: Nerodia cyclopion
  • Length: 30 – 45 in
  • Venomous: No

Probably among the least common water snakes in Missouri, the Mississippi green water snake has a range restricted to the southeastern corner of the state. They are mostly greenish-brown in color with yellow half-moon shaped markings on their backs. Mostly due to habitat loss, they have an endangered status in Missouri.

The Mississippi Green Water Snake prefers living in swamps where it feeds on frogs, fish, salamanders, crayfish, and other swamp life.

7. Western Mud Snake

Western Mud Snake | Peter Paplanus | Flickr | CC BY 2.0
  • Scientific name: Farancia abacura reinwardtii
  • Length: 40 – 54 in
  • Venomous: No

Like several other species of water snakes in Missouri, this snake is found only in Southeastern Missouri. The Western mud snake has a shiny black back but it’s belly is brightly colored red and reddish-pink.

Western mud snakes are semi-aquatic and feed primarily on a specific species of salamander called the three-toed Amphiuma. This giant salamander can reach 30 inches or more in length. Read about a similar species of giant salamander, the hellbender, in this article.

8. Water Moccasin

Water Moccasin
  • Scientific name: Agkistrodon piscivorus
  • Length: 24 – 48 in
  • Venomous: Yes

The Western Cottonmouth, which one of 3 subspecies of the water moccasin (Agkistrodon piscivorus), is one of only 5 venomous snakes found in the state of Missouri. They are found in Southern and Southeastern Missouri, and near the Ozark region of the state.

Water Moccasin/Cottonmouth | U.S. Fish & Wildlife Service Southwest Region

Water Moccasins are dark brown or black on top and the same on their bellies. Younger snakes can have a light pattern on their backs but tend to get darker as they mature. They feed on fish, amphibians, and reptiles like other water snakes, but these snakes are highly venomous and a bite can be fatal if not treated quickly. If you see one or aren’t sure what species it is, when in doubt you should always avoid snakes just to be safe.


Well that about does it for Missouri water snakes. There may be a species we missed, but we think these are the most common ones you’d come across in the state. As you saw, the only venomous one on the list is the last one, the Water Moccasin.

You may also like:  4 Types of Water Snakes in Virginia (Pictures)

Thanks for reading! Be sure to check out some of our other articles if you enjoy reading about wildlife!