Black Snakes in North Dakota 

Written by Hannah Ward
Updated: March 31, 2023
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North Dakota is a stunning state in the Upper Midwest region of the United States. It forms part of the Great Plains which stretch across the Western region, with much of the state composed of grassland and prairies. 

There are many different types of animals in North Dakota, including snakes, of which there are eight species, including one that is venomous. If you’re out exploring the state, then you’re likely to want to know which snakes you might encounter. Read on to learn about the black snakes of North Dakota!

Prairie Rattlesnake (Crotalus viridis)

The only venomous snake in the state is the prairie rattlesnake. Also called the western rattlesnake, These snakes can grow to lengths of up to 5 feet! They have tan or light brown bodies with black or dark brown markings. The prairie rattlesnake lives in the Southwestern region of North Dakota. Look for them on prairies, grasslands, and in rocky outcroppings.

A brown prairie rattlesnake , coiled and ready to strike, against a neutral background od dirt and small pebbles.

Praise rattlesnakes can grow to lengths of up to 5 feet!


The bite of the prairie rattlesnake contains powerful venom which is both hemotoxic and neurotoxic and causes serious tissue damage. Make no mistake, these snakes are dangerous! Their prey consists of small mammals, including prairie dogs, rabbits, squirrels, and rats.

Bullsnake (Pituophis catenifer sayi)

One of the longest snakes in North Dakota is the bullsnake, a subspecies of the gopher snake. Bullsnakes are 3-6 feet long and are yellow with dark brown or black markings. They live in the Western half of the state in woodlands, prairies, and grasslands. They are constrictors who prey on small mammals, birds, bird eggs, and rodents.

A coiled light brown  with darker markings bullsnake in a natural setting of long golden grass.

Bullsnakes are constrictors who prey on small mammals, birds, bird eggs, and rodents.


Bullsnakes react aggressively when they feel threatened. When they detect anything too big for them to eat they instantly assume that it is a predator. If they can’t get away safely, will assume a defensive position. This involves raising their head and neck up off the ground to make themselves look as large as possible while vibrating their tail, which, under the correct conditions, mimics the sound of a rattlesnake.

Plains Garter Snake (Thamnophis radix)

Another black snake in North Dakota is the plains garter snake which can be black, brown or greenish-grey with horizontal yellow and orange stripes and vertical black bars on its lips. They are usually 18 to 36 inches long with slender bodies. The plains garter snake lives in prairies and meadows throughout the state, typically near a source of water.

aAplans garter snake, back with horizontal stripes ( one of each, visible) of orange and red  running the length of its body, slithering among downed reeds in what appears to a body of stagnant water.

The plains garter snake lives in prairies and meadows throughout the state, typically near a source of water.

©Alyssa Metro/

Plain’s garter snake’s prey consists of earthworms, slugs, and small amphibians. However, they will also sometimes prey on small mammals and birds. Widely known as one of the most “cold tolerant” snakes in the U.S., plains garter snakes often emerge from brumation to bask in the sun on warm days. These snakes are most active between April and October when they are not in brumation.

Common Garter Snake (Thamnophis sirtalis)

The common garter snake is another garter snake in North Dakota. These snakes are 18 to 32 inches long with a varied appearances. They can be green, black, or brown with three yellowish stripes. They can also have red blotches on their sides.

Common garter snakes occur in scattered locations across the state – mainly in the Northwest and the Southern regions. They live in a wide variety of habitats but are most often found near a permanent water source such as streams and rivers. As they are diurnal you’re most likely to see common garter snakes from morning through late afternoon.

A common garter snake (mostly a dull grey to black on top with a yellowish underbelly) slithering in grass

Common garter snakes are


, so you’re most likely to see them from morning through late afternoon.


Common garter snakes are not dangerous to humans but they are toxic to their prey. They contain a mild venom-like substance in their saliva which they use to incapacitate prey such as toads. Conversely, common garter snakes are immune to the venom that is produced by toads! If you are bitten by a common garter snake it is not usually serious, with the most common symptoms being swelling and itching in the affected area.

Plains Hognose Snake (Heterodon nasicus)

The final black snake in North Dakota is the plains hognose snake, which is also known as the western or prairie hognose snake. They are 15 to 25 inches long and are typically tan or light brown with darker brown or black markings. Although plains hognose snakes resemble prairie rattlesnakes, the most distinctive difference is found in the shape of their snouts, as plains, hognose snakes have distinctly upturned snouts!

A frontal shot of a plains hognose snake's upturned snout

The plains hognose snake has a distinctly upturned snout.


Plains hognose snakes live in scattered locations across North Dakota, albeit with greater prevalence in the Western region of the state. They are most often found in the Badlands and along rivers where there is loose and sandy soil for them to burrow into.

Although they can sometimes flatten their neck like a cobra when they are disturbed, plains hognose snakes are not dangerous to humans. However, they are mildly venomous to their prey using venom which is produced and injected by rear fangs which are located at the back of the mouth.

Other Reptiles Found in North Dakota

North Dakota is home to amphibians and reptiles that can be found in various habitats. Even though they may not be immediately visible, they could still be present in the surroundings.

For instance, frogs and turtles could be swimming at the bottom of rivers and wetlands, lizards could be seen entering burrows, and snakes might be found hiding in tall grass.

North Dakota’s sole venomous snake is the prairie rattlesnake, which has a color range that includes greenish-gray, brown, red, or all-brown. The snake features dark, oval-shaped marks enclosed by white borders. They are generally found in grasslands, sagebrush regions, and on the elevated rocky surfaces of buttes.

With that said, here is a list of other reptiles found in North Dakota:

The photo featured at the top of this post is © DMartin09/


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About the Author

Hannah is a writer at A-Z animals where her primary focus is on reptiles, marine life, mammals, and geography. Hannah has been writing and researching animals for four years alongside running her family farm. A resident of the UK, Hannah loves riding horses and creating short stories.

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