With temperatures rising, you might be ready to finally lose your and other heavy layers on the hiking trails. It feels great to get some sun on your skin, but there are more critters out there at this time of year who want to sink their fangs into your flesh. In recent years, tick-borne diseases like Lyme disease have been grabbing a lot of headlines and for good reason – more than 63,000 cases of Lyme reported to CDC in 2022 alone – but it’s not the only cause for concern when there are ticks on the trail.

If you’re exploring out west this spring and summer, there are other tick-related illnesses to watch out for, such as Colorado Tick Fever which, despite the name, isn’t limited to the Centennial State. Colorado Tick Fever is rare, but it’s helpful to recognize the symptoms if you’re going to be spending a lot of time outdoors, at altitude. Read on for the causes, signs and symptoms of Colorado Tick Fever, plus how to avoid it on the trails.

Colorado Tick Fever is a very rare virus spread by infected Rocky Mountain wood ticks. These ticks are found in low-growing vegetation across the western US and western Canada at elevations between 4,000 and 10,000 feet above sea level. In the US, wood ticks are found in Colorado, Wyoming, Montana, Utah, Idaho and parts of California, Washington and Oregon.

Wood ticks, which are distinguishable by their bright red, teardrop-shaped body, are most active between March and July. They contract the virus by feeding on affected.