Ticks are common in Colorado’s diverse outdoor environments, from mountain trails to grassy plains. Understanding their peak seasons and prevalent species helps residents and outdoor enthusiasts take precautions to minimize encounters and safeguard health.
Peak Tick Activity in Colorado
Tick activity in Colorado increases from early spring through late fall, peaking in spring and early summer. Tick numbers typically rise in March, reaching their peak in May and June. While most pronounced during these months, ticks can remain active year-round in milder conditions, adapting to local temperatures and moisture levels.
Environmental factors significantly influence tick prevalence. Ticks are often found in brushy areas, woodlands, grassy areas, and shrublands where animal hosts frequently travel. In Colorado, ticks are common at higher elevations, up to 10,000 feet, and exist across the entire state. Their populations vary depending on location and habitat.
Common Colorado Tick Species and Health Concerns
Colorado hosts approximately 30 tick species, but the Rocky Mountain wood tick and American dog tick are most frequently encountered by humans. The Rocky Mountain wood tick (Dermacentor andersoni) thrives in wooded areas, meadows, and shrublands, including at higher elevations. It is the primary vector for Colorado tick fever, the most common tick-transmitted illness in the region.
Colorado tick fever is a viral infection with flu-like symptoms (fever, chills, headache, body aches) typically appearing three to seven days after a bite. Most individuals experience mild illness and recover fully; there is no specific medication to treat the virus.
Rocky Mountain spotted fever, a bacterial disease, is transmitted by the Rocky Mountain wood tick, American dog tick, and brown dog tick, though it is quite rare in Colorado. Tularemia, another bacterial disease, can also be transmitted by both the Rocky Mountain wood tick and the American dog tick.
The American dog tick (Dermacentor variabilis) is common in grassy areas and along wooded trails. It is known to transmit Rocky Mountain spotted fever and tularemia, but not Lyme disease. The blacklegged tick, responsible for Lyme disease elsewhere, is not found in Colorado.
Protecting Yourself During Tick Season
Proactive measures reduce the risk of tick bites when enjoying Colorado’s outdoors. Wearing appropriate clothing acts as a physical barrier; long-sleeved shirts, long pants tucked into socks, and light-colored attire to spot ticks easily. Apply insect repellents containing DEET, picaridin, or permethrin (on clothing) for added protection. Stay on marked trails and avoid dense brush, tall grasses, and heavily wooded areas to minimize exposure to tick habitats.
After outdoor activities, conduct a thorough tick check on yourself, children, and pets, focusing on warm, hidden areas like armpits, groin, hairline, behind the knees, and the belly button. Showering after returning indoors can wash off unattached ticks. Placing outdoor clothing in a hot dryer for at least 10 minutes eliminates lingering ticks.
If a tick is attached, use fine-tipped tweezers to grasp it close to the skin and pull straight upward with steady pressure. Avoid twisting or squeezing, then clean the bite area.