Calarat Challenge Trail Running Festival

The Holy COW Trail Stampede is a trail running event held in Westminster, Colorado, featuring distances including a 5K and a 10-mile race. Participants enjoy a fun, community-focused atmosphere with a western theme, running through scenic trails near the Westminster Promenade Terrace. All runners re..

Dirt Circus - Boulder is a free community running event held in Boulder, Colorado, celebrating local trail running culture. Organized by UltraSignup, the event features a social group run with options of a casual 4.5-mile or 10k route through the local area. Beyond the run, participants enjoy a fest..

The Byers Peak Stampede Half Marathon & 5K Run takes place in Fraser, Colorado, nestled in the Rocky Mountains about 60 miles from Denver. The event features a challenging half marathon and a 5K race, both primarily on dirt roads and trails with stunning mountain views. The half marathon starts at a..

The Westminster Night Trail in Westminster, Colorado, is a vibrant night trail running event held at Standley Lake. Celebrating its 12th year, it offers distances of 50K, 35K, half marathon, 10K, and 5K, all on 100% packed dirt trails featuring a mix of single-track and bike paths. Runners experienc..

Front Range Ultra Dayze is an ultra-running festival held in Loveland, Colorado, featuring a variety of ultra-distance events including 50k, 100-mile, 200-mile, and timed races up to 100 hours. The course is a flat, fast 2-mile loop through Centennial Park and River’s Edge Natural Area, mostly on di..

The American Heroes Run, held in Longmont, Colorado, is a patriotic running event commemorating the events of 9/11. It features a variety of distances including a 100-mile ultra with a 30-hour cutoff, a 24-hour run, marathon, half-marathon, 9.11-mile, and 5K races. The course is a flat, fast 1.05-mi..