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8 Common Types of Ticks in Colorado (With Pictures)

Ticks are arachnids, part of the mite superorder Parasitiformes. They are external parasitic bugs with eight legs that feed on the blood of other animals, including mammals, birds, and some amphibians and reptiles. They are related to spiders but have oval, flat bodies that can swell up when they feed. There are 28 species of known ticks in Colorado. However, sometimes additional species are found outside their common habitats.

In Colorado, ticks mostly exist outdoors during the spring and early summer months. They live in habitats where their host animals travel, including woodlands, grassy areas, brushy areas by fields, and shrublands. Make sure to check your clothing and your body when you’re outdoors in tick habitats!

This article will explore more details about 8 common species of ticks found in Colorado, including if you have to watch out for them since some can carry diseases!

8 Common Ticks in Colorado

The 8 common species of ticks in Colorado are the Winter tick, American Dog tick, Rocky Mountain wood tick, Rabbit tick, Lone Star tick, Relapsing Fever tick, Brown Dog tick, and Ear tick.

1. Winter Tick

Winter ticks on a dead moose
Winter ticks on a dead moose | image by alexisgodin via iNaturalist | CC BY 4.0

Scientific name: Dermacentor albipictus

The Winter tick has a large distribution in North America and can be found throughout most of Colorado. They are reddish-brown with a patterned back and grow around 0.25 inches long. However, after feeding, females can reach up to 0.75 inches long.

These ticks commonly feed on large animals, including horses, elk, moose, mountain goats, and deer. They are a one-host species where they will attach to one animal as a larva and stay there until fully grown. Because of this characteristic, they are rarely a threat to humans.

2. American Dog Tick

American dog tick
American dog tick | image by USFWS Midwest Region via Flickr

Scientific name: Dermacentor variabilis

You can mainly find the American Dog Tick in most eastern U.S. states, including eastern Colorado counties and regions of the Rocky Mountains. They prefer areas without tree cover, such as walkways, trails, and grassy fields.

These ticks are reddish-brown to brown with gray or silver markings on their backs. Females are typically larger than males, averaging 0.19 inches in length. However, after feeding, they can expand to 0.59 inches long and 0.39 inches wide. They can survive up to 2 years without feeding.

Common hosts they feed on include dogs, humans, small rodents, and raccoons. They are one of the major ticks causing Rocky Mountain spotted fever but can also cause Colorado tick fever and tick paralysis.

3. Rocky Mountain Wood Tick

Rocky mountain wood tick
Rocky mountain wood tick | image by Yellowstone National Park via Flickr

Scientific name: Dermacentor andersoni

As their name suggests, this tick is a major cause of the Rocky Mountain spotted fever. However, they also contribute to spreading Colorado tick fever and tick paralysis. They are one of the most common species that feed on people. They also prefer porcupines, small rodents, deer, cattle, horses, and other large animals.

You can find the Rocky Mountain wood tick in most counties throughout the western half of Colorado, especially in areas of elevations from 4,000 to 10,500 feet. They are normally brown but can turn grayish after feeding.

4. Rabbit Tick

Scientific name: Haemaphysalis leporispalustris

As their name suggests, the Rabbit tick prefers feeding on jackrabbits or cottontail rabbits. However, they are also known to feed on birds, white-tailed deer, and dogs. Although they rarely feed on humans, they can transmit the following diseases:

  • Rocky Mountain spotted fever
  • Q fever
  • Tularemia
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You can find them throughout the state anywhere their preferred hosts live. These ticks are reddish-tan and grow around 0.125 inches.

5. Lone Star Tick

Lonestar tick
Lone star tick | image by Anthony Zukoff via Flickr | CC BY-SA 2.0

Scientific name: Amblyomma americanum

The Lone Star tick is a highly invasive species in the state and exists mainly in Colorado’s extreme eastern and southeastern regions. They prefer habitats with heavy vegetation and wooded areas, including piles of wood and debris they can hide under. You can find them on your property if these conditions exist.

These ticks have a wide range of hosts they will feed on, including frequently biting humans, dogs, and livestock. They are brownish in color and get their name from the white dot representing a “lone star” on the back of female adults.

6. Relapsing Fever Tick

Scientific name: Ornithodoros hermsi

The Relapsing Fever tick prefers feeding on rock squirrels, chipmunks, rats, mice, and other rodents. This soft tick often spreads the pathogen for Relapsing fever. Although generally rare in humans, infections can occur if you camp in areas infected by rodents. In fact, Colorado is one of the top five states with reported cases of this tick-borne disease.

You can typically find these ticks in hunting cabins or coniferous forest habitats at elevations between 1,500 and 8,000 feet. They are generally gray and feed in a short period of around 15 to 20 minutes. These ticks are also known to live up to 4 years without a meal.

7. Brown Dog tick

Brown dog tick
Brown dog tick | image by gailhampshire via Flickr | CC BY 2.0

Scientific name: Rhipicephalus sanguineus

The Brown Dog tick is reddish-brown without any noticeable markings. They are typically 0.125 inches but can grow up to 0.5 inches and change to a blue-gray color after feeding.

These ticks prefer to feed on dogs. Although rarer, they can feed on humans or domestic and wild mammals. Unlike other tick species, the Brown Dog tick can reproduce indoors in building cracks and crevices and are often found in homes or kennels. They can be found throughout Colorado in areas where dogs live.

8. Ear Tick

Scientific name: Otobius megnini

As their name suggests, the Ear tick is a soft-bodied tick that prefers infecting the ear canals of animals. Although they prefer pronghorns, they also feed on humans, cattle, mules, sheep, goats, and horses. There are no connected diseases to this tick, however, you can develop other infections as a result of their feeding.

These ticks are typically brown or black with scattered gray, white, or silver patterns on their backs. Adults can grow up to 0.4 inches in length.

Other Ticks in Colorado

While the above list is of common tick species in Colorado, there are others you can find in the state. Those listed below, are often referred to as either soft-bodied or hard-bodied ticks, and by their scientific name.

Other Soft Ticks:

  • Otobius lagophilus
  • Otobius megnini
  • Argas cooleyi
  • Argas radiatus 
  • Carios concanensis 
  • Carios kelleyi

Other Hard Ticks:

  • Dermacentor parumapertus
  • Haemaphysalis chordeilis
  • Ixodes angustus
  • Ixodes baergi
  • Ixodes brunneus
  • Ixodes cookei
  • Ixodes howelli
  • Ixodes marmotae
  • Ixodes ochotonae
  • Ixodes kingi
  • Ixodes sculptus
  • Ixodes soricis
  • Ixodes texanus
  • Ixodes spinipalpis

FAQs (and Tips) About Colorado Ticks

1. How Do I Remove a Tick?

Ticks have barbed mouthparts that firmly latch onto your skin, so you should remove them with care. If the barbs remain, it can easily lead to infection. The best process to remove a tick is to:

  • Use a fine-tipped tweezer to grasp the tick as close to your skin as possible
  • Slowly and steadily pull the tick up from your skin without crushing, twisting, or jerking it
  • Disinfect the area the tick was on
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2. How Do I Kill a Tick?

Never crush a tick with your fingers! Since the resulting secretions can cause diseases. After removing a tick, you want to put it in alcohol, in a sealed container, or flush it down the toilet. If the ticks are on your clothes, you can also dry your clothes in high heat or wash them in hot water to kill the ticks.

3. How Do I Prevent Ticks from Feeding on Me?

When you go outside in tick-infested habitats, make sure to cover up all your skin in protective clothing. You can also wear tick repellent. Lastly, always do a tick check since it can take them a few hours to settle before feeding. When conducting a tick check, make sure to check:

  • All your clothes
  • Under your arms
  • The back of your knees
  • Between your legs
  • In your hair
  • Behind your ears

4. When is Tick Season in Colorado?

Tick season starts in spring and continues into early summer in Colorado. You can start seeing ticks active around March and they are most abundant during a peak in May. They are common in areas with a lot of brush, so be extra mindful when hiking in the mountains.

5. What Are the Symptoms of Colorado Tick Fever?

The Colorado tick fever virus is a common illness from ticks in Colorado that you need to be cautious about. There are around 200 cases reported per year. Symptoms include:

  • Fever and chills
  • Headaches
  • Lethargy
  • Weakness and fatigue
  • Rashes on most people

It’s best to seek medical attention as soon as possible in case you experience severe complications.

6. Can I Get Lyme Disease From Colorado Ticks?

The Black-legged tick or Deer tick (Ixodes scapularis) is the most common tick that transmits Lyme disease to humans. Although this species is not listed as a Colorado tick, it does not mean you won’t accidentally encounter one that has migrated on the back of its host. According to the Centers for Disease Control (CDC), there were eight confirmed cases of Lyme disease in Colorado in 2019.

7. What Are Other Tick-Borne Diseases in Colorado?

Besides Colorado Tick Fever and Lyme disease, other tick-borne diseases you need to watch out for in Colorado include:

  • Powassan virus disease
  • Q-Fever
  • Rocky Mountain Spotted Fever
  • Tick-Borne Relapsing Fever
  • Tularemia