Holy Cow Trail Stampede

The Boulder Rez Marathon, held at Boulder Reservoir in Boulder, Colorado, offers a scenic and mostly flat course with only 200 feet of elevation gain. Runners enjoy trails and dirt roads alongside the reservoir, with stunning views of the water and the Rocky Mountains. The event features multiple di..

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 trails. Beyond running, the festival offers foo..

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

The Bluffs 8K Trail Run is a challenging race held at Bluffs Regional Park in Lone Tree, Colorado. The course features rolling hills and beautiful views, with a mix of fine crushed gravel and some rugged, steep sections. The race starts and finishes near the Prairie Sky Park parking lot.Participants..

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..

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..