Ticks are present in the Denver metropolitan area and the surrounding Front Range region. Ticks thrive in the natural environments bordering the city, such as the foothills and open space parks. The risk profile is significantly lower than in regions like the Northeast United States, where the primary vector for Lyme disease is common. Understanding the specific species active near Denver is the first step in effective prevention.
Local Tick Presence and Common Species
The most frequently encountered species in the Denver area is the Rocky Mountain Wood Tick (Dermacentor andersoni), which is generally active in the spring and early summer, from March through June. This tick prefers subalpine elevations and the brushy areas of foothills and mountains. The American Dog Tick (Dermacentor variabilis) is also present throughout the region, favoring grassy fields and the edges of wooded areas.
These arachnids do not fly or jump; they engage in a behavior called “questing,” where they climb onto low-lying vegetation like tall grass or shrubs and wait for a host to brush past. They are often found along trails and in areas with high deer and rodent populations, which serve as hosts. This includes large natural parks like Cherry Creek State Park or open spaces that maintain native grasslands and dense brush.
Ticks can be active at elevations ranging from the plains up to about 10,500 feet, covering all areas where Denver residents typically recreate. While the most intense period of activity is concentrated in the late spring, ticks can be encountered any time the temperatures are consistently above freezing. The Brown Dog Tick (Rhipicephalus sanguineus) is a species that primarily targets dogs but can be found in homes and kennels.
Disease Transmission and Risk Levels
Lyme disease is rarely acquired locally in Colorado because the Blacklegged Tick (Ixodes scapularis), the primary vector, is not established in the state. Cases of Lyme disease reported in Colorado are almost always traced back to exposure that occurred while traveling out-of-state. Therefore, the focus for local risk shifts to other pathogens.
The most common tick-borne illness in the region is Colorado Tick Fever (CTF), a viral disease transmitted by the Rocky Mountain Wood Tick. Symptoms typically appear three to seven days after a bite and can include fever, chills, headache, and body aches. A characteristic feature of CTF is a “saddleback” fever, where symptoms subside for a few days before returning.
Rocky Mountain Spotted Fever (RMSF) is a bacterial illness that can be transmitted by the Rocky Mountain Wood Tick and the American Dog Tick, though it is rare in Colorado. Another potential threat is Tularemia, a bacterial infection that can be spread by the same ticks. While the risk of contracting any of these diseases in the Denver area is relatively low, recognizing the symptoms of locally relevant illnesses like CTF is important for timely medical attention.
Effective Prevention Strategies
Minimizing the risk of tick exposure requires preparation before heading outdoors and thorough checks afterward. When hiking or spending time in grassy or brushy areas, wearing light-colored clothing makes it easier to spot a tick crawling on the fabric. It is advisable to wear long pants and tuck the cuffs into your socks to create a barrier against questing ticks.
Using an EPA-registered insect repellent is a highly effective measure for personal protection. Repellents containing DEET, picaridin, or oil of lemon eucalyptus can be applied to skin. Products containing permethrin can be used to treat clothing and gear for a longer-lasting effect. Staying in the center of trails and avoiding walking through tall grass and dense underbrush will reduce the chance of contact.
After returning indoors, performing a full-body check is important, paying close attention to areas like the scalp, ears, armpits, and groin. A shower taken within two hours of outdoor activity can help wash off unattached ticks. If a tick is found attached, it should be removed immediately using fine-tipped tweezers by grasping the tick as close to the skin’s surface as possible and pulling upward with steady, even pressure.