Trail Running calendar near Boulder 2025-2026
We have found 63 Trailruns within 80 miles of Boulder. See below where and when you can find the races.
Distance (km)
Articles
Belgian Ultrarunner Karel Sabbe's Record-Breaking Pacific Crest Trail Run Showcased in New YouTube Documentary
Explore Karel Sabbe's record-breaking Pacific Crest Trail run in a riveting documentary. Jour..
Trail Running: How it Can Help Reduce Stress and Anxiety
Trail running is an effective way to reduce stress, anxiety, and improve physical and mental he..
Trail Running vs. Road Running: Which One Is Right For You?
When it comes to running, there are two primary options to choose from: trail running and road..
Niwot's Challenge is a highly demanding ultramarathon held annually in Sedalia, Colorado, along the South Platte River in the Front Range. Modeled after the grueling Barkley Marathons, it features a mostly off-trail course requiring advanced navigation skills using map and compass, with no GPS allow..
The Greenland Trail Races, held annually in May at Greenland Open Space in Larkspur, Colorado, offer four race distances: 4 miles, 8 miles, 25K, and the 50K ultramarathon, known as Colorado's fastest 50K. The course features wide, smooth dirt trails through native grasslands, ponds, oak hills, and p..
Endure Trail Runs, hosted by the Human Potential Running Series, is an annual event held at Mueller State Park in Divide, Colorado. The 2026 edition features a unique 12-Hour timed race where runners draw colored balls to determine their next loop, running as many miles as possible within the time l..