The Bull Snake (Pituophis melanoleucas) is the largest snake found in Montana and Wyoming, reaching over seven feet in length. The head is small and somewhat pointed. The eyes are orange or brick red with round pupils.

The color pattern consists of a tan to light brown body with 41 to 66 brown, black or reddish brown blotches. On the sides, below the blotches are rows of similarly colored spots. There are 27 to 37 rows of keeled dorsal scales. This color and scale description should sound familiar as it is very similar to the Prairie Rattlesnake.

Except for the shape of the head and eyes, they look very much alike and the Bull Snake seems to know this as they imitate the behavior of rattlesnakes to their own advantage. They will vibrate the end of their tail in dry brush or leaves, making a sound similar enough to the rattle of the rattlesnake. This fools many of those who hear it into reacting as they would to a rattlesnake.

To Breed Or Not To Breed
The Bull Snake is also often called the Gopher Snake. When biologists study various species they try to distinguish those animals that interbreed with one another and produce young, from other animals with which they cannot successfully interbreed. Individuals within a species can vary in appearance enough to make us think they are different species, but when we realize they can successfully interbreed we know they are the same species.

The standard scientific name for the Bull Snakes in Bighorn Canyon is Pituophis catenifer sayi but the preferred scientific name is Pituoplius melanoleucas. This is not a case of two different names for the same species. It is a case of what was thought to be one species actually being two species. And to make it more confusing, some of the literature was written before they were thought of as two different species and some after. And sometimes all the scientists do not agree on whether there are two species or not. Andjust to make it a bit more complex some species change through time.

Giving Birth
Mating takes place in the spring and clutches of 3 to 24 eggs are laid between June and August. The eggs are deposited in lose soil or sandy burrows or under large rocks or logs and hatch after 64 to 79 days of incubation. They hatch unattended and must fend for themselves. They may live as long as 20 years.

The prey base of Bull Snakes include ground squirrels, mice, wood rats, moles, small cottontail rabbits, nestling birds, eggs, and lizards. The Bull Snakes are constrictors and kill their prey by squeezing around them or if in a burrow they will press the prey against the burrow wall and then ingest them.

Habitat And Range
They can be found in the plains grassland, sagebrush, sandhills, riparian areas, marshes, rocky canyons, and mountain shrublands as well as suburban and agricultural areas. Their range is from east of the continental divide and from Canada to Mexico down through the central plains. When looking at the bull snakes, gopher snakes, and pine snakes that make up the genus Pituophis they seem to be found throughout the west (the gopher snakes) and southeast and as far north as the pine barrens in New Jersey(the pine snakes).

A Fascinating Study
Bull Snakes hibernate in deep crevices or dens in large aggregations, sometimes sharing this space with eastern yellowbelly racers, pale milk snakes, garter snakes and rattlesnakes. This communal hibernation along with the imitative behavior of rattlesnakes by flattening their head, taking on the strike posture, hissing and rattling their tails offers fascinating potential for further study. Now where are the scientists that want to get into these winter dens?

Last updated: February 24, 2015

Contact the Park

Mailing Address:

Bighorn Canyon National Recreation Area Headquarters Office
PO Box 7458

Fort Smith, MT 59035


(307) 548-5406

Contact Us