Bull snakes in Colorado: Pictures and Where they Live

When threatened, the Bullsnake rears up in an S-shape, hisses and vibrates its tail to mimic the venomous rattlesnake.
© Markparker1983/Shutterstock.com

Written by Cindy Rasmussen

Updated: July 31, 2023

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Colorado is known for the Rocky Mountains, but there are also forests, grasslands, prairies and deserts. These varied habitats are home to around 30 different species of snakes but the bull snake is one of the most common snakes in Colorado. Let’s find out more about the bull snakes in Colorado.

What is a bull snake?


Bull snakes are the largest snakes in Colorado.

©Christopher Joe Brown/Shutterstock.com

Bull snakes are the largest snake in Colorado; they are sometimes called gopher snakes as well (to be specific, the bull snake is a subspecies of the gopher snake). They are typically 4-6 feet long, but some can get up to 8 feet! And they are not skinny like a jump rope; they are heavy-bodied snakes, with most being between 2-3 lbs. but some have weighed in at 10 lbs. Bull snakes are tan or cream-colored with dark brown patterned splotches. They look similar to rattlesnakes, and because they sometimes move their tail to mimic rattlesnakes, they are sometimes mistaken for them.

Where can you find bull snakes in Colorado?

Bull snakes are found throughout Colorado except for high in the Rocky Mountains. While bull snakes are found mostly in eastern Colorado, other gopher snakes (such as the Great Basin gopher snake) live in the western half of the state. They live in grasslands, woodlands, and on farms. Farmers actually don’t mind these large snakes because they eat mice, moles, and rabbits. You can also find bull snakes in residential areas, especially the yards of homes that border grasslands.

Do bull snakes live in every county in Colorado?

Bull snakes and other gopher snakes are one of the most widespread snakes in Colorado, but they are not in every county. They are not in the counties where the Rocky Mountains are. There are few reptiles and amphibians that can survive in the colder temps that occur in the mountains. The western terrestrial garter snake is the only snake that lives in the Rocky Mountains, and it lives in the lower elevations of Rocky Mountain National Park.

Western terrestrial garter snakes are the only snakes that live in the higher elevations of the Rocky Mountains.


Where do most bullsnakes live?

Bull snakes live across the Great Plains of the United States and into the northern part of Mexico. They prefer places where they can burrow, like prairies, grasslands, farmland, and forest floors.

The Denver Post reported on a story from a man in Westminster, CO, that found 41 bull snakes in his friend’s crawl space! The man went to get rid of “a snake” that was seen in the muddy crawl space, but what he found was 41 of them all curled up, probably still brumating. The man carefully put them all in a large trash bag and then released them several miles away. So maybe your crawl space may be where the most bull snakes can be found!

What states besides Colorado do bullsnakes live in?

The range of bull snakes includes Montana, North Dakota, Wyoming, South Dakota, Nebraska, Colorado, Kansas, Oklahoma, Texas, New Mexico, Missouri, Iowa, Minnesota, Wisconsin, Illinois, and Indiana. As noted earlier, bull snakes are one of nine subspecies of gopher snakes that are all closely related. Gopher snakes generally live across the western United States, northern Mexico, and in western Canada.

Are bull snakes poisonous or venomous?

No, bull snakes are not poisonous; they are non-venomous snakes. The only venomous snakes in Colorado are prairie rattlesnakes, Massasauga rattlesnakes, and midget faded rattlesnakes. Bull snakes mimic rattlesnakes by rattling their tails, but they do not have an actual rattle at the end of their tail. They look similar to rattlesnakes and are sometimes killed because people fear they are venomous rattlesnakes. If you want to tell the difference, look for the triangular head of the rattlesnake and vertical eye slits that look like a cat’s eyes. Bull snakes will have a narrower, rounder head and a round black pupil. If you don’t care to get close enough to see their eyes, it is safest to keep your distance from all snakes!

Bullsnake vs Rattlesnake
Bull snakes look a lot like rattlesnakes but there are differences like the triangle head and eyes with vertical slits like cat eyes.

Are bullsnakes dangerous?

No, bullsnakes are not dangerous. They avoid people and are not overly aggressive. If they are approached, they will give fair warning before striking. You will hear a loud hiss and may hear their fake rattle. You may also be surprised to hear a loud grunting noise that is unique to bull snakes. Bull snakes can bite, but they do not have long fangs like rattlesnakes. If you get bitten by a snake that you don’t recognize, seek medical attention. Their bites are painful, but because they are not venomous, there should not be any life-threatening reactions.

Are bull snakes constrictors?

Yes. Bull snakes are constrictor snakes like a boa constrictor; they will wrap themselves around their prey until it can no longer breathe, then they swallow their prey whole. Bull snakes are not picky eaters and will eat mice, moles, gophers, lizards, and birds.

Best Pet Snake option - boa constrictor

Boa constrictors are constrictor snakes that wrap around their victims. There are not any Boa constrictors in Colorado, but bull snakes are constrictors.

©Natalia Kuzmina/Shutterstock.com

Can bullsnakes constrict humans?

Although they are heavy-bodied snakes, they are nowhere near as big as a boa constrictor, so a human would have no trouble untangling from a bull snake if it ever tried to constrict. Boa constrictors, on the other hand, can get to be 13 feet long and weigh up to 100 pounds!

How big is the biggest bullsnake?

When threatened, the Bullsnake rears up in an S-shape, hisses and vibrates its tail to mimic the venomous rattlesnake.

When threatened, the Bullsnake rears up in an S-shape, hisses, and vibrates its tail to mimic the venomous rattlesnake.


According to the Guinness World Records, the longest bull snake was 2.6 meters (that is 8.5 feet!). Your average sofa is 6-8 feet, so its tail (or head) would be hanging off the edge of some sofas! That is a big snake! While they can grow long, bull snakes rarely reach 10 pounds in weight.

Can bull snakes get into your house in Colorado?

They could, but it is not likely. In May of 2021, a woman in Grand Junction, CO, shared a photo on social media of a large tan snake with dark brown markings making its way into her garage. She was seeking advice on what kind of snake it was. Many people chimed in, identifying it as a bull snake. She was able to “shoo” it away with a broom before it made itself comfortable in her garage or inviting itself into her home!

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".

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