Rattlesnakes in Colorado: A Guide to Identification and Safety Tips

Rattlesnakes are a common sight in Colorado, as the state is home to three different species of these venomous snakes. While they are often feared by hikers and outdoor enthusiasts, rattlesnakes play an important role in the ecosystem and should be respected rather than feared. Understanding their behavior, habitat, and diet can help people coexist with these fascinating creatures.

Rattlesnakes slither through rocky terrain in Colorado, basking in the warm sunlight

Colorado is home to three different species of rattlesnakes: the prairie rattlesnake, the western massasauga rattlesnake, and the midget-faded rattlesnake. Each species has its own unique characteristics, including differences in size, coloration, and habitat. Despite their differences, all three species are venomous and can pose a danger to humans and pets if provoked or threatened.

While rattlesnakes can be found throughout Colorado, they are most commonly found in the western half of the state. They prefer habitats that are dry and rocky, such as grasslands, shrublands, and desert areas. Understanding where and when rattlesnakes are most likely to be encountered can help people avoid potentially dangerous encounters.

Key Takeaways

  • Colorado is home to three species of venomous rattlesnakes: the prairie rattlesnake, the western massasauga rattlesnake, and the midget-faded rattlesnake.
  • Rattlesnakes are most commonly found in dry, rocky habitats in the western half of the state.
  • Understanding the behavior, habitat, and diet of rattlesnakes can help people avoid dangerous encounters and coexist with these important members of the ecosystem.

Rattlesnakes Overview in Colorado

Colorado is home to three species of rattlesnakes: the western massasauga rattlesnake, prairie rattlesnake, and the midget-faded rattlesnake. Each species has its own unique characteristics, habitats, and behaviors.

The prairie rattlesnake is the most common species found in Colorado, and it is also the largest. Adults can range between 3.3 and 5 feet in length. The coloration of the prairie rattlesnake is highly variable and can be greenish-gray, olive green, greenish-brown, light brown, or yellow. All variations have dark blotches on the body that turn into rings near the tail. The prairie rattlesnake is found throughout the state, from the eastern plains to the western mountains.

The western massasauga rattlesnake is a smaller species, with adults reaching a length of only 2 feet. This species is found in the eastern part of the state, in grasslands, scrublands, and rocky hillsides. The western massasauga rattlesnake has a distinctive pattern of dark brown blotches on a light brown background.

The midget-faded rattlesnake is the smallest of the three species found in Colorado, with adults reaching a length of only 16 inches. This species is found in the southwestern part of the state, in desert habitats. The midget-faded rattlesnake has a gray or tan background color with a series of dark brown blotches on its back.

It is important to note that rattlesnakes are venomous and can be dangerous if provoked. If you encounter a rattlesnake in the wild, it is best to keep a safe distance and allow the snake to move away on its own. If you or someone else is bitten by a rattlesnake, seek medical attention immediately.

Types of Rattlesnakes Found in Colorado

Colorado is home to three species of rattlesnakes: the Prairie Rattlesnake, the Midget Faded Rattlesnake, and the Massasauga Rattlesnake. Each species has its own unique characteristics and can be found in different regions of the state.

Prairie Rattlesnake

The Prairie Rattlesnake (Crotalus viridis) is the most common rattlesnake found in Colorado. They are typically 3.3 to 5 feet in length, with highly variable coloration ranging from greenish-gray to yellow. They are found throughout the state, from the eastern plains to the western mountains. Prairie Rattlesnakes are known for their loud rattles and are often found in grasslands, rocky outcroppings, and near water sources.

Midget Faded Rattlesnake

The Midget Faded Rattlesnake (Crotalus oreganus concolor) is the smallest rattlesnake found in Colorado, typically measuring less than 2 feet in length. They are found in the western part of the state, particularly in the Four Corners region. Midget Faded Rattlesnakes are usually gray or tan in color and have a distinctive black and white banded tail. They are often found in rocky areas and can be difficult to spot due to their small size.

Massasauga Rattlesnake

The Massasauga Rattlesnake (Sistrurus catenatus tergeminus) is the rarest rattlesnake found in Colorado, with a limited range in the southeastern part of the state. They are typically 1 to 2 feet in length, with a gray or brown coloration and a distinctive row of dark blotches down their back. Massasauga Rattlesnakes are found in wetland areas and are known for their mild-mannered temperament.

In conclusion, while rattlesnakes can be dangerous, they are an important part of Colorado’s ecosystem. It’s important to be aware of their presence and to take precautions when hiking or camping in rattlesnake habitat. By understanding the different types of rattlesnakes found in Colorado, you can better appreciate and respect these fascinating creatures.

Habitats and Distribution

Rattlesnakes coiled among rocky outcrops in Colorado's high desert. Sagebrush and scrub oak dot the landscape, with distant mountains in the background

Rattlesnakes in Colorado are found in a variety of habitats, including grasslands, scrublands, rocky hillsides, plains, sandhills, and deserts. Each species has its own specific habitat preferences and distribution within the state.

Eastern Plains

The eastern plains of Colorado are home to the prairie rattlesnake (Crotalus viridis), which is the most common rattlesnake species in the state. These snakes prefer open grasslands and prairies, but can also be found in agricultural fields and along roadsides. They are also known to den in prairie dog burrows, rock crevices, or caves.

Rocky Mountains

The western slope of the Rocky Mountains is home to the western rattlesnake (Crotalus oreganus), which prefers rocky outcroppings, grasslands, rocky stream crossings, and ledges. These snakes are also known to den in rock crevices or caves.

Great Basin

The Great Basin region of Colorado is home to the midget-faded rattlesnake (Crotalus concolor). These snakes prefer scaling canyon walls with ease and are typically found near sandstone cliffs and on rocky outcroppings near the Green or Colorado River. The snakes prefer south-facing areas with sunlight and protection from shrubs and groundcover.

Overall, rattlesnakes in Colorado can be found in a variety of habitats and regions throughout the state. It is important to be aware of their presence and take precautions when spending time outdoors in these areas.

Behavior and Diet

A rattlesnake slithers through dry grass, hunting small rodents. Its scales glisten in the sun, blending with the rocky terrain

Rattlesnakes are ambush predators that rely on their venomous bite to immobilize their prey. They are known for their distinct rattle, which is used as a warning signal to potential predators. Rattlesnakes are generally not aggressive and will only attack if they feel threatened.

Hunting Tactics

Rattlesnakes use their heat-sensing pits to locate warm-blooded prey, striking with lightning speed and precision. They are known for their ability to strike from a coiled position, with some species able to strike up to two-thirds of their body length. Rattlesnakes are also capable of swallowing prey whole, aided by their flexible jaws that can open up to 150 degrees.

Dietary Preferences

The diet of rattlesnakes primarily consists of small mammals, such as mice, rats, and rabbits. However, they have been known to feed on birds, lizards, and other snakes as well. Rattlesnakes are able to go for long periods without food, sometimes up to a year, due to their slow metabolism.

It is worth noting that rattlesnakes play an important role in their ecosystem as both predator and prey. They help control rodent populations, which can cause damage to crops and spread disease. Additionally, rattlesnakes are preyed upon by a variety of animals, including birds of prey, coyotes, and other snakes.

Overall, understanding the behavior and diet of rattlesnakes is important for those living in areas where they are commonly found. By being aware of their hunting tactics and dietary preferences, individuals can take steps to avoid encounters with these venomous snakes.

Reproduction and Lifespan

A rattlesnake slithers through the dry grass of the Colorado desert, its scales glistening in the sunlight. Nearby, a group of baby rattlesnakes bask in the warmth, their small, vibrant bodies blending into the sandy

Mating Season

Rattlesnakes in Colorado mate in the spring, typically between April and May. During this time, males will compete for females by engaging in combat dances, where they intertwine their bodies and push against each other. The winner will then mate with the female.

Gestation and Birth

After mating, the female rattlesnake will carry her eggs inside her body for about three months. Once the eggs are ready to hatch, the female will give birth to live young, typically between six and twelve babies.

Growth and Lifespan

Baby rattlesnakes are born fully formed and ready to hunt. They will grow quickly, shedding their skin several times a year as they mature. Rattlesnakes can live up to 20 years in the wild, but many do not survive that long due to predation, disease, or human interference. As they age, their venom becomes more potent, making them even more dangerous to humans and other animals.

Rattlesnakes are an important part of the ecosystem in Colorado, but it’s important to be cautious around them. By understanding their reproductive habits and lifespan, people can better appreciate these fascinating creatures while also staying safe.

Conservation Status

A rattlesnake slithers through dry grass in the Colorado desert, blending into its surroundings with its tan and brown scales


The three species of rattlesnakes found in Colorado, the Prairie Rattlesnake, the Massasauga Rattlesnake, and the Western Rattlesnake, are facing threats to their survival. The primary threat to these species is habitat loss due to human activities such as urbanization, agriculture, and oil and gas development. Road mortality is also a significant threat to rattlesnakes.

Another threat to the rattlesnake population is illegal collection for the pet trade. This practice is illegal in Colorado, and the state has strict laws and regulations in place to protect these species.

Protection Efforts

Colorado Parks and Wildlife (CPW) has implemented several measures to protect rattlesnakes in the state. The state agency has designated several areas as critical habitat for rattlesnakes, where human activities are restricted to protect the species. CPW also conducts research on rattlesnakes to better understand their biology, ecology, and habitat requirements.

The state has also implemented strict regulations on the collection and possession of rattlesnakes. It is illegal to collect, possess, or sell rattlesnakes without a permit from CPW. The state agency also works with law enforcement agencies to enforce these regulations and prevent illegal collection and trade of rattlesnakes.

Overall, the conservation status of rattlesnakes in Colorado is a concern, and efforts are being made to protect these species from further decline. It is essential to raise awareness about the importance of these species in the ecosystem and the need for their conservation.

Safety and First Aid

Bite Prevention

Rattlesnakes are common in Colorado, and it’s important to take precautions to avoid being bitten. Here are some tips to help prevent rattlesnake bites:

  • Wear protective clothing, such as boots and long pants, when hiking or working in areas where rattlesnakes may be present.
  • Stay on designated trails and avoid tall grass, brush, and rocks where snakes may be hiding.
  • Keep pets on a leash and avoid letting them explore areas where snakes may be present.
  • Use caution when approaching or handling any snakes, as even non-venomous snakes can bite.

First Aid for Snakebites

If someone is bitten by a rattlesnake, it’s important to seek medical attention immediately. Here are some first aid tips to help in the meantime:

  • Keep the affected limb immobilized and at or below heart level to slow the spread of venom.
  • Remove any tight clothing or jewelry near the bite site.
  • Clean the bite wound with soap and water, but do not apply ice, heat, or suction to the wound.
  • Do not give the victim any food, drink, or medication unless directed by a medical professional.

Remember, the best way to avoid a rattlesnake bite is to stay alert and avoid contact with snakes whenever possible. If you do encounter a snake, give it plenty of space and do not attempt to handle or interact with it.

Legal Aspects

Hunting Regulations

In Colorado, rattlesnakes are considered a game animal, and hunting them is legal with the proper license and permits. However, the Colorado Parks and Wildlife (CPW) has established strict regulations for hunting rattlesnakes. According to Colorado Public Radio, it is only legal to kill a rattlesnake if it poses a threat. All other snakes are protected by law as nongame wildlife.

The CPW requires a small game hunting license and a $25 permit to hunt rattlesnakes. The permit allows for the take of up to four snakes per year, and hunters must follow strict guidelines on the capture and handling of the snakes. It is also important to note that hunting rattlesnakes is only allowed during the designated hunting season, which typically runs from May 16th to September 30th.

Wildlife Protection Laws

Colorado has strict wildlife protection laws in place to ensure the safety and preservation of all native species, including rattlesnakes. According to Uncover Colorado, rattlesnakes are Colorado’s only native poisonous snake, and they play an important role in the ecosystem. As such, it is illegal to harm, capture, or kill rattlesnakes without a permit.

It is also important to note that rattlesnakes are protected under the Federal Endangered Species Act, and it is illegal to harm or kill them on federal lands. This includes national parks, national forests, and other federally managed lands. Violating these laws can result in severe penalties, including fines and imprisonment.

Overall, it is important to be aware of the hunting regulations and wildlife protection laws when it comes to rattlesnakes in Colorado. By following these guidelines, hunters and outdoor enthusiasts can help ensure the safety and preservation of these important native species.

Research and Studies

Venom Research

Researchers at the University of Colorado Boulder have been studying the venom of rattlesnakes in Colorado to better understand how the reptiles evolve over time to keep up with prey resistance to their venom. The study found that rattlesnakes tap genetically diverse venom toolbox to keep up with evolving prey [1]. The researchers analyzed the venom of 28 rattlesnakes from six different populations across Colorado and found that the snakes had a wide range of venom types and concentrations.

The study’s findings have important implications for understanding the evolution of venomous snakes and how they interact with their prey. The researchers hope that their work will help to develop new treatments for snakebite victims and improve our understanding of the ecological role of venomous snakes.

Ecological Impact Studies

Another area of research on rattlesnakes in Colorado is their ecological impact. Researchers are interested in understanding how rattlesnakes fit into the ecosystem and how their presence or absence affects other species. For example, a study by the Colorado Natural Heritage Program found that rattlesnakes play an important role in controlling rodent populations [3].

The study found that areas with rattlesnakes had lower rodent populations than areas without rattlesnakes. This is because rattlesnakes are one of the primary predators of rodents, and their presence helps to keep their populations in check. The study also found that rattlesnakes are an important food source for other predators, such as hawks and eagles.

Overall, research on rattlesnakes in Colorado is ongoing and has important implications for understanding the ecology and evolution of these fascinating reptiles. By studying their venom and ecological impact, researchers are shedding light on the complex relationships between rattlesnakes and their environment.

[1] To keep up with evolving prey, rattlesnakes tap genetically diverse venom toolbox

[3] Rattlesnakes in Colorado: Where they are, what to do if you’re bitten

Frequently Asked Questions

What types of venomous snakes can be found in Colorado?

Colorado is home to three species of venomous snakes: the prairie rattlesnake, the massasauga rattlesnake, and the western rattlesnake. All three species are pit vipers and have a triangular-shaped head and vertical pupils.

How can one safely remove rattlesnakes from their property in Colorado?

It is recommended to contact a licensed professional to remove rattlesnakes from your property. Attempting to remove the snake yourself can be dangerous and should be avoided.

What are the peak activity months for rattlesnakes in Colorado?

Rattlesnakes in Colorado are most active from April to October, with the peak activity months being June, July, and August.

Are there any rattlesnake species that inhabit the Denver area?

Yes, the prairie rattlesnake can be found in the Denver area. However, they are not commonly found in urban areas and typically inhabit more rural environments.

At what altitudes in Colorado are rattlesnakes no longer present?

Rattlesnakes in Colorado are generally not found above 7,000 feet in elevation. However, there have been rare sightings of rattlesnakes at higher altitudes.

Which regions in Colorado have the highest population of rattlesnakes?

Rattlesnakes can be found throughout Colorado, but they are most commonly found in the western and southern regions of the state. Areas with rocky terrain and plenty of sun exposure are ideal habitats for rattlesnakes.