Watch Out for the 5 Poisonous Snakes in Missouri

Written by Kyle Glatz
Updated: March 21, 2023
© Rusty Dodson/
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Missouri is famous for the Missouri River, from which it derives its name along with its culture, but most people don’t know it is home to a great number of reptiles. While some of these creatures, like the western mud snake, are simply beautiful to look at, other snakes in this part of the United States are dangerous. That’s why we will identify and examine the five venomous snakes in Missouri. You’ll know exactly which snakes to look out for if you find yourself in this part of the world!

The Venomous Snakes in the United States

Coral snakes are brightly colored and have distinctive bands, but they are the rarest venomous snake in the United States.


The United States is home to four genera of venomous snakes. These deadly snakes are:

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Each of these snakes is found within the borders of the contiguous U.S., but not all of them are in each state. Some states lack members from this list, while others have numerous species from each genus. The latter is the case with Missouri, as we will show you throughout this article.

How Many Types of Snakes Live in Missouri?

Missouri has 38 different types of snakes that live throughout the state. The vast majority of them are non-venomous and serve an important role in the food chain. They help keep rodent and small mammal populations low and serve as meals for eagles and other animals.

Although it might be helpful to have some of these animals in one’s backyard, some snakes are rather unwelcome. After all, Missouri is home to a few species of venomous, sometimes called poisonous, snakes.  

The 5 Venomous Snakes in Missouri

The five venomous snakes in Missouri are the copperhead, timber rattlesnake, cottonmouth, western pygmy rattlesnake, and eastern massasauga rattlesnake. All these snakes are pit vipers and share some qualities, such as their triangular heads and cat-like pupils.

Every one of these snakes should be considered dangerous. Although some of them are rarely fatal, all of them can cause severe injuries, long-lasting disabilities, and death when they bite humans.

We’re going to examine each of these five snakes. We’ll show you what they look like, which one is most dangerous, and other important information.

Southern Copperhead

Snakes in Mississippi - Southern Copperhead (Agkistrodon contortrix)
Copperheads are difficult to detect meaning they are stepped on frequently

©Jay Ondreicka/

SizeColorUnique Qualities
2ft-4ft long– Brown, tan, yellow
–  Dark brown or red hourglass-shaped blotches on its back
– Blend in well with leaves and soil
– Great camouflage in dirt and debris  

Copperhead snakes are a common sight in many parts of Missouri. These snakes measure about 2ft on average, and their colors can vary quite a bite. You may find light brown, yellow, or copper colors, but you can also find darker copperheads.

Their colors and dark blotches help them blend in with their surroundings. These snakes are frequently stepped on because people have trouble seeing them.

The copperhead that lives in Missouri is often called Osage copperhead, but that’s an antiquated designation. This species is not distinct from the southern copperhead. However, this snake is rather dangerous. A bite from this snake requires a trip to the hospital.  

Timber Rattlesnake

Rattlesnakes While HIking - Timber Rattlesnake
Timber rattlesnakes prefer wooded areas and are capable of growing up to 5 feet

©Joe McDonald/

SizeColorUnique Qualities
3ft-7ft long– Dark zig-zag patterns set against brown, gray, or pinkish skin– Known for its rattling and defense posture
– Snake does not always rattle before biting

Timber rattlesnakes are the largest venomous snakes in Missouri, and they can regularly reach 5ft in length. As their name suggests, they are usually found in wooded areas. When a human approaches a rattlesnake, the snake will rattle to scare them away in some cases.  

However, rattlesnakes do not rattle all the time and they may strike without warning. These snakes have a deadly hemotoxic venom that requires emergency treatment to survive. Most people survive rattlesnake bites with treatment, but disabilities are common.


Moccasin Snake
Cottonmouths prefer staying close to water and are also known as water mocassins

©Nathan A Shepard/

SizeColorUnique Qualities
– Between 2-3ft long
– May grow up to 5ft long
– Olive, black, brown– White mouth that they open when threatened
– Patch of white on the chin
– Arrow-shaped head

The cottonmouth snake is also called the water moccasin. As one might imagine, cottonmouth snakes are often found near bodies of water. Although some people claim these snakes are aggressive and will chase down humans to bite them, that’s not exactly true.

The cottonmouth snake will start a bluff charge to scare away humans so it can ensure its safety. These snakes can deliver a venomous bite that will cause serious harm to people.

Western Pygmy Rattlesnake

pygmy rattlesnake
The western pygmy rattlesnake is short and thick and gives off a buzzing sound rather than a warning rattle

©Gerald A. DeBoer/

SizeColorUnique Qualities
1ft-2ft long– Gray base color with an orange and brown stripe running down the middle
– Brown splotches down the length of the body
– Has a rattle on the end of its tail
– Thich-bodied like other rattlesnakes

Pygmy rattlesnakes are very small venomous snakes, measuring about 2ft at their longest. Although these snakes are rare and can’t make a lot of venom, they’re still worth knowing about.

The rattling noise from a pygmy rattlesnake apparently sounds more like a buzzing than a rattling. Also, you’ll notice that despite being short, this snake has a thick body. The pygmy rattlesnake can deliver a medically significant bite that requires treatment.

Eastern Massasauga

A massasauga rattlesnake can grow up to 2.5 feet.


SizeColorUnique Qualities
2ft-2.5ft long– Brown, grey, black, tan
– Dark brown or black splotches down the back and sides
– Known for its small rattle and resemblance to other snakes

Eastern massasaugas are rattlesnakes known for being somewhat rare in Missouri because they live near the shrinking marsh areas. They are dangerous animals, but they are known for being less aggressive than other types of rattlesnakes.

These snakes aren’t as long as timber rattlesnakes, but they’re bigger than pygmy rattlesnakes.  

How Many People Do Poisonous Snakes in Missouri Kill Each Year?

Can Rattlesnakes Kill You With Their Venom
Thanks to modern medicine venomous snakebite fatalities in Missouri are extremely low

©Joe McDonald/

On average, fewer than one person in Missouri dies as a result of a venomous snakebite each year. Roughly 250 venomous snakebites occur in Missouri each year. Fortunately, the advances in modern medicine largely prevent deaths in the United States.

Even though the number of snakebite deaths is low, they can only stay that way with proper education. Do not try to handle snakes that you’re not familiar with, and always go seek medical help if you get a snakebite.

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Massasauga on a rock
A juvenile western Massasauga rattlesnake from northern Missouri. Massasaugas have colors and markings that include tan, gray, or brown with dark brown or black splotches.
© Rusty Dodson/

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About the Author

I'm a freelance writer with 8 years of experience. I've written in a variety of niches such as managed service providers, animals, and retail distribution. I graduated from Rowan University in 2014 . When I'm not working, I enjoy playing video games, reading, and writing for fun.

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