Boulder Rez Marathon

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 trails. Beyond running, the festival offers foo..

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 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..

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 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..