Byers Peak Stampede Half Marathon

The Calarat Challenge Trail Running Festival takes place in Jamestown, Colorado, at the Cal-Wood Education Center, a nonprofit dedicated to outdoor education. Held over Labor Day weekend, the event features multiple trail races including a half marathon, 10K, 5K, Kids 1K, and combination races like..

Devil on the Divide is a two-distance trail race in Empire, Colorado, offering 50K and 22K options. The course features dirt, largely single-track, point-to-point routes that reach elevations above 13,000 feet, with about 6,500 feet of climbing on the 50K and around 3,400 feet on the 22K. Celebrated..

Cirque Series returns to Arapahoe Basin, Colorado, for a high-alpine mountain race. On White River National Forest trails above Keystone, the course runs about 9 miles with roughly 2,411 feet of elevation gain, starting at Mountain Goat Plaza at the base of A-Basin. Racers ascend via summer road to..

NedNed Trail Fest in Nederland, Colorado, at 151 East Street, offers a trail half marathon (13.3 miles with 1,408 feet of elevation gain), a 10K (6.3 miles, 712 ft gain), and a 5K (family-friendly, leashed dogs allowed). Runners wind through Old Town Nederland on dirt roads and single-track trails a..

The Snow Mountain Ranch Trail Running Festival, held at the YMCA of the Rockies in Granby, Colorado, offers a scenic and challenging trail running experience with race distances of 50K, 33K, Half Marathon, 10K, and 5K. Set amidst rolling hills, golden aspen groves, and mountain vistas, the courses f..

The Colleen De Reuck XC Classic is a cross country running event held annually at Harlow Platts Community Park in Boulder, Colorado. Honoring renowned distance runner Colleen De Reuck, the race promotes health, fitness, and celebrates local Olympians, with 2025 honoring 2012 Olympic marathoner Yoshi..