Snakes in Colorado: Rocky Mountain Reptiles

Colorado has a pleasant surprise for you, with 27 species of snakes slithering around the Centennial State. Are you ready to discover the diverse world of these fascinating reptiles?

From the notorious rattlesnakes to the lesser-known wandering garter snakes, Colorado’s snake population offers a unique variety for reptile admirers. And don’t worry, most of these serpents are more inclined to keep their distance than cause any trouble.

So let’s dive into the fascinating realm of Colorado’s snakes. Lace up your boots, and prepare to explore the scaly wonders hidden in the Rockies!

#	Name	Details	Image
1	Blackneck Garter Snake (Thamnophis cyrtopsis)	Size: 16-42 inches (40-107 cm) Color: Olive-green or brown with dark stripes and a black neck Habitat: Near water sources, including streams, rivers, and ponds Behaviour: Diurnal and semi-aquatic
2	Central Plains Milksnake (Lampropeltis gentilis)	Size: 16-32 inches (40-81 cm) Color: Reddish-brown with alternating light and dark bands Habitat: Prairies, woodlands, and rocky hillsides Behaviour: Nocturnal and terrestrial
3	Coachwhip Snake (Masticophis flagellum)	Size: Up to 8 feet (2.4 meters) Color: Variety of colors, including tan, brown, pink, and black Habitat: Deserts, grasslands, and woodlands Behaviour: Diurnal and fast-moving
4	Common Garter Snake (Thamnophis sirtalis)	Size: Up to 3-4 feet (0.9-1.2 meters) Color: Green or brown with three yellow stripes Habitat: Wet and moist habitats, including marshes, fields, and forests Behaviour: Diurnal, active, hibernates in winter
5	Glossy Snake (Arizona elegans)	Size: Up to 5 feet (1.5 meters) Color: Gray or brown with dark blotches Habitat: Desert, grassland, and scrub habitats Behaviour: Nocturnal and terrestrial
6	Great Basin Gophersnake (Pituophis catenifer deserticola)	Size: Up to 4.5 feet (1.4 meters) Color: Yellowish or pale brown with dark blotches Habitat: Semi-arid deserts, grasslands, and rocky areas Behaviour: Diurnal and burrowing
7	Great Plains Rat Snake (Pantherophis emoryi)	Size: Up to 5 feet (1.5 meters) Color: Gray or brown with dark blotches Habitat: Grasslands, prairies, and open woodlands Behaviour: Primarily nocturnal and terrestrial
8	Kingsnake (Lampropeltis getula)	Size: Up to 8 feet (2.4 meters) Color: Black or dark brown with white or yellow bands Habitat: Various habitats, including forests, grasslands, and deserts Behaviour: Nocturnal, terrestrial, and good climbers
9	Lined Snake (Tropidoclonion lineatum)	Size: Up to 20 inches (51 cm) Color: Gray or tan with dark stripes Habitat: Grasslands, prairies, and urban areas Behaviour: Nocturnal and fossorial
10	Long-Nosed Snake (Rhinocheilus lecontei)	Size: Up to 30 – 52 inches (76 – 132 cm) Color: Black or brown with red, cream, or white bands Habitat: Semi-arid or desert areas, grasslands, scrublands, and rocky terrain Behaviour: Nocturnal, terrestrial, and non-aggressive
11	Massasauga Rattlesnake (Sistrurus catenatus)	Size: 18-30 inches (46-76 cm) Color: Gray or light brown with dark banding Habitat: Grasslands, marshes, and woodland areas Behaviour: Nocturnal, secretive, and terrestrial
12	Midget Faded Rattlesnake (Crotalus oreganus concolor)	Size: Up to 30 inches (76 cm) Color: Light gray or tan with faded blotches Habitat: Rocky slopes, sagebrush deserts, and grasslands Behaviour: Nocturnal and terrestrial
13	Night Snake (Hypsiglena torquata)	Size: Up to 20 to 36 inches (51 to 91 cm) Color: Light gray, beige or pale brown with dark blotches Habitat: Deserts, grasslands, shrublands, and rocky areas Behaviour: Nocturnal and secretive
14	Northern Water Snake (Nerodia sipedon)	Size: Up to 4.5 feet (1.4 meters) Color: Brown or gray with dark bands or blotches Habitat: Aquatic habitats, such as rivers, lakes, ponds, and marshes Behaviour: Nocturnal and semi-aquatic
15	Plains Black-headed Snake (Tantilla nigriceps)	Size: 7-15 inches (18-38 cm) Color: Gray or light brown with a black head Habitat: Desert scrub, grasslands, and woodlands Behaviour: Nocturnal and burrowing
16	Plains Garter Snake (Thamnophis radix)	Size: 16-28 inches (41-71 cm) Color: Brown or gray with yellow or orange stripes Habitat: Grasslands, wetlands, and areas near water sources Behaviour: Diurnal, good swimmers, and semi-aquatic
17	Prairie Rattlesnake (Crotalus viridis)	Size: 20-50 inches (51-127 cm) Color: Greenish or brownish with dark bands and a rattle on the tail Habitat: Prairies, grasslands, and scrublands Behaviour: Nocturnal, terrestrial, and ambush predators
18	Ringneck Snake (Diadophis punctatus)	Size: 12-15 inches (30-38 centimeters) Color: Gray or dark brown with yellow or orange ring around the neck Habitat: Forests, grasslands, and urban areas Behaviour: Nocturnal and secretive, often hiding under rocks or logs
19	Smooth Green Snake (Opheodrys vernalis)	Size: 14-20 inches (36-51 cm) Color: Bright green with a lighter belly Habitat: Grasslands, meadows, and open woodlands Behaviour: Diurnal, terrestrial, and good climbers
20	Southwestern Blackhead Snake (Tantilla hobartsmithi)	Size: Up to 15 inches (38 cm) Color: Light brown or gray with a black head Habitat: Semi-arid habitats, including grasslands, woodlands, and desert scrub Behaviour: Nocturnal and secretive, burrowing in soil and leaf litter
21	Striped Whipsnake (Masticophis taeniatus)	Size: Up to 6 feet (1.83 meters) Color: Black, green or blue with yellowish stripes Habitat: Deserts, grasslands, and rocky areas Behaviour: Fast-moving, diurnal, and ground-dwelling
22	Terrestrial Garter Snake (Thamnophis elegans)	Size: Up to 3.3 feet (1 meter) Color: Striped in various shades of green, brown, or gray Habitat: Grasslands, woodlands, and forests near water sources Behaviour: Diurnal and sometimes semi-aquatic
23	Texas Blind Snake (Leptotyphlops dulcis)	Size: Up to 12 inches (30 cm) Color: Pink or purple with a silver belly Habitat: Found in various habitats such as grasslands, deserts, and suburban areas Behaviour: Nocturnal and fossorial
24	Variable Ground Snake (Atractus trilineatus)	Size: 8-14 inches (20-36 cm) Color: Gray or brown with three light-edged stripes Habitat: Grassy or rocky habitats, tropical forests Behaviour: Terrestrial and secretive
25	Western Hognose Snake (Heterodon nasicus)	Size: Up to 2.5 feet (0.76 meters) Color: Brown or tan with dark blotches Habitat: Grasslands, prairies, and semi-arid environments Behaviour: Diurnal and terrestrial, known for its characteristic “hognose” and playing dead when threatened
26	Western Ribbonsnake (Thamnophis proximus)	Size: 18-30 inches (46-76 cm) Color: Black or dark brown with three bright yellow or white stripes Habitat: Semi-aquatic habitats, wetlands, marshes, and grasslands near water Behaviour: Diurnal, swift, and good swimmer
27	Yellow-bellied Racer (Coluber constrictor flaviventris)	Size: Up to 6 feet (1.8 meters) Color: Olive green to blue-gray dorsally and bright yellow on the ventral side Habitat: Grasslands, forests, and scrublands Behaviour: Diurnal, actively foraging

27 Snakes You Can Find in Colorado

In the state of Colorado, a fascinating array of serpents can be found slithering through its diverse landscapes. From venomous to harmless, each species has its unique story to tell. Below, we’ll explore the wonders of these often misunderstood creatures of Colorado, from their natural habitats and behaviors to the challenges they face in our changing world.

1. Blackneck Garter Snake

The Blackneck Garter Snake (Thamnophis cyrtopsis) is a mildly venomous, diurnal, and semi-aquatic reptile measuring between 16-42 inches in length. Its olive-green or brown coloring features dark stripes and a distinctive black neck. Commonly found near water sources such as streams, rivers, and ponds of Colorado, it primarily feeds on amphibians, fish, and invertebrates. As a live-bearing species, it produces 10-40 offspring per litter. Although rear-fanged, its venom is not dangerous to humans. Its conservation status is currently classified as Least Concern.

2. Central Plains Milksnake

Its scientific name is Lampropeltis gentilis. These cool creatures are between 16-32 inches long and have a stunning reddish-brown color with alternating light and dark bands. They love hanging out in prairies, woodlands, and rocky hillsides. As night owls, they’re nocturnal and terrestrial. They snack on small mammals, birds, reptiles, and amphibians. When it comes to family, they lay eggs in clutches of 3-13. Don’t worry, they’re non-venomous, and their conservation status is “Least Concern.”

3. Coachwhip Snake

The Coachwhip Snake, scientifically known as Masticophis flagellum, is a swift, diurnal serpent native to deserts, grasslands, and woodlands. Growing up to 8 feet (2.4 meters) long, this non-venomous snake displays a variety of colors, from tan, brown, pink, to black. As adept hunters, Coachwhip Snakes primarily feed on lizards, small mammals, and birds. Mating leads to egg clutches ranging from 3-15. Despite their striking appearance, their conservation status remains classified as least concern.

4. Common Garter Snake

The Common Garter Snake (Thamnophis sirtalis) is a 3-4 feet (0.9-1.2 meters) non-aggressive and mildly venomous reptile with a green or brown body and three yellow stripes. Inhabiting wet and moist habitats like marshes, fields, and forests of Colorado, these diurnal snakes hibernate during winter to escape the cold. Their diet consists of frogs, fish, earthworms, and small mammals. Uniquely, these snakes birth live young, producing 10-40 per litter. Although venomous, they pose no threat to humans and are currently listed as a species of least concern for conservation.

5. Glossy Snake

The Glossy Snake (Arizona elegans) is a non-venomous, nocturnal reptile found in desert, grassland, and scrub habitats across North America. Measuring up to 5 feet (1.5 meters) in length, this resident of Colorado boasts a gray or brown coloration with dark blotches. As a terrestrial creature, the Glossy Snake feeds on small mammals, lizards, and other snakes, and reproduces by laying egg clutches of 3 to 12. With a conservation status of ‘least concern’, it continues to thrive in its native regions.

6. Great Basin Gophersnake

The Great Basin Gophersnake (Pituophis catenifer deserticola) is a non-venomous reptile that can grow up to 4.5 feet (1.4 meters) in length. It has a yellowish or pale brown color, adorned with dark blotches. This diurnal and burrowing snake primarily inhabits semi-arid deserts, grasslands, and rocky areas. Its diet consists of rodents, birds, and eggs. During reproduction, females lay egg clutches of 3-11 offspring. The species is currently considered of least concern in terms of conservation status.

7. Great Plains Rat Snake

The Great Plains Rat Snake (Pantherophis emoryi) is a non-venomous snake species that can reach up to 5 feet (1.5 meters) in length. They exhibit gray or brown coloring with dark blotches and inhabit grasslands, prairies, and open woodlands of Colorado. These snakes are primarily nocturnal and terrestrial, preying on rodents, birds, and eggs to maintain a healthy diet. Females lay eggs in clutches of 5-20, contributing to their conservation status of “least concern.”

8. Kingsnake

The Kingsnake (Lampropeltis getula) is a strikingly banded reptile found in various habitats, such as forests, grasslands, and deserts. Measuring up to 8 feet (2.4 meters) in length, they feature black or dark brown scales contrasted by white or yellow bands. As nocturnal, terrestrial creatures, Kingsnakes are also adept climbers. Their diet consists of rodents, birds, lizards, and other snakes. Though non-venomous, their reproduction entails laying 3-24 eggs per clutch. Their conservation status is currently least concern.

9. Lined Snake

The Lined Snake (Tropidoclonion lineatum) is a small, non-venomous species, growing up to 20 inches (51 cm). It has a gray or tan colored body with dark stripes, adapted to living in grasslands, prairies, and urban areas. Being nocturnal and fossorial, this reptile primarily feeds on earthworms, slugs, and soft-bodied insects. Lined Snakes reproduce by laying eggs in clutches of 2-12. With a conservation status of least concern, they remain a thriving species.

10. Long-Nosed Snake

The Long-Nosed Snake (Rhinocheilus lecontei) is a non-venomous reptile that reaches lengths of 30-52 inches (76-132 cm). Its distinct black or brown coloration features red, cream, or white bands. Commonly found in semi-arid or desert areas, grasslands, scrublands, and rocky terrain, this nocturnal creature is terrestrial, non-aggressive, and primarily feeds on rodents, lizards, and small mammals. Long-nosed snakes reproduce by laying clutches of 3-10 eggs, and their conservation status is listed as least concern.

11. Massasauga Rattlesnake

The Massasauga Rattlesnake (Sistrurus catenatus) is a small venomous snake, growing up to 18-30 inches (46-76 cm) in length. Exhibiting gray or light brown coloring with dark banding, it thrives in habitats such as grasslands, marshes, and woodland areas. This nocturnal, secretive, and terrestrial snake predominantly feeds on small mammals, lizards, and amphibians. Its reproduction involves giving birth to live young in litters ranging from 5-20. With hemotoxic venom, the snake currently has a conservation status of “Least Concern.”

12. Midget Faded Rattlesnake

The Midget Faded Rattlesnake (Crotalus oreganus concolor) is a small, venomous snake growing up to 30 inches (76 cm) long. It has a light gray or tan coloration with faded blotches, making it well camouflaged in its habitat of rocky slopes, sagebrush deserts, and grasslands. The snake is nocturnal and terrestrial, preying on small mammals, lizards, and birds. It reproduces by laying eggs in clutches of 4-6, and its venom contains hemotoxins. The conservation status is currently listed as least concern.

13. Night Snake

The Night Snake (Hypsiglena torquata) is a mildly venomous, nocturnal reptile found in deserts, grasslands, shrublands, and rocky areas. Measuring 20-36 inches in length, it sports a light gray, beige, or pale brown coloration with dark blotches. This secretive snake primarily feasts on lizards, small snakes, and amphibians. Its reproduction cycle involves laying eggs in clutches of 3-9. While the Night Snake’s venom is not dangerous to humans, its conservation status remains at the least concern level.

14. Northern Water Snake

The Northern Water Snake (Nerodia sipedon) is a non-venomous reptile that can grow up to 4.5 feet (1.4 meters) in length. It is characterized by its brown or gray color with dark bands or blotches. This nocturnal and semi-aquatic species can be found in a variety of aquatic habitats, including rivers, lakes, ponds, and marshes. Its diet consists of fish, amphibians, and invertebrates. Northern Water Snakes reproduce by laying eggs in clutches of 10-30, and currently have a conservation status of least concern.

15. Plains Black-headed Snake

The Plains Black-headed Snake (Tantilla nigriceps) is a small, non-venomous reptile, measuring 7-15 inches (18-38 cm) in length. It is characterized by its gray or light brown coloration and distinctive black head. This nocturnal and burrowing snake inhabits desert scrub, grasslands, and woodlands, where it primarily feeds on insects, centipedes, and spiders. Reproduction involves laying eggs in small clutches. Despite its unique appearance, it is currently classified as a species of least concern in terms of conservation.

16. Plains Garter Snake

The Plains Garter Snake (Thamnophis radix) is a non-venomous reptile characterized by its brown or gray color with yellow or orange stripes. Typically measuring 16-28 inches (41-71 cm) in length, it thrives in grasslands, wetlands, and areas near water sources. These diurnal, semi-aquatic snakes are known for their swimming prowess. They feed primarily on earthworms, amphibians, fish, and invertebrates. Mating results in live births, producing 6-80 offspring per litter. Currently, their conservation status is of least concern.

17. Prairie Rattlesnake

The Prairie Rattlesnake (Crotalus viridis) is a venomous snake inhabiting prairies, grasslands, and scrublands. Typically measuring 20-50 inches (51-127 cm) in length, it features a greenish or brownish coloration with dark bands and a distinctive rattle on its tail. As nocturnal, terrestrial, and ambush predators, they mainly feed on small mammals, birds, and reptiles. These live-bearing snakes, with 4-21 offspring per litter, pose a potential danger to humans though their venom is usually not fatal. Currently, they hold a conservation status of Least Concern.

18. Ringneck Snake

The Ringneck Snake (Diadophis punctatus) is a small, mildly venomous serpent, measuring 12-15 inches (30-38 centimeters) in length. Exhibiting a gray or dark brown coloration with a distinct yellow or orange ring around its neck, this species prefers habitats including forests, grasslands, and urban areas. As nocturnal, secretive creatures, Ringneck Snakes are found hiding under rocks or logs, feeding on small invertebrates such as insects, worms, and slugs. Reproducing by laying 3-10 eggs per clutch, this snake is presently classified as least concern in terms of conservation status.

19. Smooth Green Snake

The Smooth Green Snake (Opheodrys vernalis) measures 14-20 inches (36-51 cm) and is characterized by its vibrant green color and lighter belly. Commonly found in grasslands, meadows, and open woodlands, this diurnal and terrestrial reptile is an adept climber. Its diet mainly consists of insects and spiders. In terms of reproduction, they lay eggs in clutches of 3-12. Though non-venomous, these snakes should be admired from afar. Fortunately, their conservation status is currently listed as ‘Least Concern.’

20. Southwestern Blackhead Snake

The Southwestern Blackhead Snake (Tantilla hobartsmithi) is a small, non-venomous snake that grows up to 15 inches (38 cm) in length. Its distinctive appearance features a light brown or gray body with a black head. Inhabiting semi-arid habitats like grasslands, woodlands, and desert scrub, this nocturnal creature is secretive and coverts, burrowing in soil and leaf litter. It feeds on invertebrates such as centipedes, spiders, and insect larvae. Southwestern Blackhead Snakes lay eggs in clutches of 1-4, and maintain a conservation status of least concern.

21. Striped Whipsnake

The Striped Whipsnake (Masticophis taeniatus) is a long, slender snake measuring up to 6 feet (1.83 meters) in length. Sporting black, green, or blue scales with yellowish stripes, it inhabits deserts, grasslands, and rocky areas of Colorado. As a fast-moving, diurnal creature, it thrives primarily on the ground, preying on lizards, small mammals, birds, and amphibians. Non-venomous in nature, it lays 3-12 eggs in each clutch. The Striped Whipsnake’s conservation status is classified as “least concern.”

22. Terrestrial Garter Snake

The terrestrial garter snake (Thamnophis elegans) is a mildly venomous, diurnal snake that grows up to 3.3 feet (1 meter) in length. Sporting stripes in various shades of green, brown, or gray, these semi-aquatic creatures inhabit grasslands, woodlands, and forests near water sources. They primarily feast on earthworms, slugs, snails, frogs, and fish. The terrestrial garter snake gives birth to live young, with 4-17 offspring per litter. Despite their venom, they are not harmful to humans, and their conservation status is classified as least concern.

23. Texas Blind Snake

The Texas Blind Snake (Leptotyphlops dulcis) is a small, non-venomous serpent, measuring up to 12 inches (30 cm) in length. Sporting a pink or purple hue with a silver belly, it can be found in various habitats including grasslands, deserts, and suburban areas. Being nocturnal and fossorial, the snake remains hidden during daylight hours. Its diet consists of ants, termites, and their larvae. A female Texas Blind Snake lays eggs in clutches of 1-7. Its conservation status is currently least concern.

24. Variable Ground Snake

The Variable Ground Snake (Atractus trilineatus) is a small, non-venomous snake measuring 8-14 inches (20-36 cm) in length. Its coloration varies between gray and brown, featuring three light-edged stripes on its back. Found in grassy, rocky habitats and tropical forests, this terrestrial reptile is secretive and elusive. Its diet consists of small amphibians and invertebrates. It reproduces by laying eggs in small clutches, but its conservation status has not yet been evaluated.

25. Western Hognose Snake

The Western Hognose Snake (Heterodon nasicus) is a mildly venomous reptile that can grow up to 2.5 feet (0.76 meters) in size. It has a distinct brown or tan color with dark blotches and is known for its characteristic “hognose.” These terrestrial snakes primarily inhabit grasslands, prairies, and semi-arid environments. Being diurnal creatures, their diet consists of amphibians, particularly toads, small mammals, reptiles, and birds. They reproduce by laying eggs in clutches of 4-23 and, despite the venom, are not considered dangerous to humans. Their conservation status is of least concern.

26. Western Ribbonsnake

The Western Ribbonsnake (Thamnophis proximus) is a slender reptile measuring 18-30 inches (46-76 cm) in length, characterized by its black or dark brown coloration adorned with three bright yellow or white stripes. Commonly found in semi-aquatic habitats such as wetlands, marshes, and grasslands near water, this diurnal creature is a swift swimmer, preying primarily on fish, frogs, and tadpoles. The non-venomous species reproduces by laying egg clutches of 3-26, and has a conservation status of ‘Least Concern’.

27. Yellow-bellied Racer

The Yellow-bellied Racer (Coluber constrictor flaviventris) is a non-venomous snake that can grow up to 6 feet (1.8 meters) long. It features an olive green to blue-gray back with a bright yellow belly, providing its descriptive common name. These diurnal reptiles inhabit grasslands, forests, and scrublands of Colorado, actively foraging during the day for a diet that includes small mammals, birds, lizards, and invertebrates. As an oviparous species, they lay clutches of 5 to 50 eggs. Currently, their conservation status is listed as Least Concern.

Nearby States:

• Snakes in Hawaii
• Snakes in Idaho

Final Words

All the 27 snakes have truly opened our eyes to the fascinating world of snakes found in Colorado. Who knew there were so many different types of these slithering reptiles, each with their own unique characteristics and habitats?

Not only did we get a chance to learn about some of the more common and well-known species, but we also delved into the lesser-known and often misunderstood ones.

So, the next time you’re out and about in Colorado, keep an eye out for these incredible creatures, and let’s continue to appreciate and protect the diverse wildlife that makes our world so interesting!

What Types of Snakes Can Be Found in Colorado and South Dakota?

In Colorado, you can find several species of snakes, including the bullsnake, prairie rattlesnake, and garter snake. South Dakota is also home to a diverse range of snakes, such as the western fox snake, prairie rattlesnake, and garter snake. Overall, snakes in south dakota and Colorado exhibit fascinating diversity.

Resources:

• Amphibians and Reptiles – Rocky Mountain
• Reptiles – Florissant Fossil Beds
• Snakes of Colorado | Museum of Natural History
• Coping With Snakes – 6.501 – CSU Extension