Boulder Rez Marathon

The Frederick Pack Burro Race is an annual 10K event held in Frederick, Colorado, celebrating the town's Miners Day heritage. The race follows a scenic course starting downtown at Fifth and Oak Streets, heading north along a trail through a tunnel to the Frederick Recreation Area, looping around Mil..

Estes Epic is a multi-event trail challenge held in Estes Park, Colorado. The weekend features a 50k bike race, a 50k trail run, a Heavy Half Marathon, and the all-in Epic Double (50k MTB and 50k Run). After a six-year break, the race returns with remote, rugged terrain, single-track trails, steep c..

Rocky’s Backyard Ultra is held at the YMCA of the Rockies Estes Park Center in Estes Park, Colorado. Runners must complete 4.167 miles in under one hour each lap, with the field reduced to a single finisher as the race continues until no others remain. The course loops around the boundary of RMNP on..

The Bear Chase Race Endurance Festival occurs at Bear Creek Lake Park in Lakewood, Colorado, offering 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K (plus the Baby Bear 10K). The mostly dirt, single-track course is described as fast by trail/ultra standards and rewards sweeping mountain views with c..

Boulder XC Series Meet 1 is a family-friendly cross-country event held at Valmont City Park (South) in Boulder, Colorado (5110 Valmont Rd). The meet offers three distances: 1K for younger runners, 3K for those up to 16, and a 5K open race, welcoming participants of all ages and abilities. It’s the f..

The Great Trailhead Foot Race 5 & 10 Miler is a trail-running event held at Bear Creek Lake Park in Lakewood, Colorado. Runners choose a 5-mile course or a 10-mile option (two laps) on single-track and dirt trails, with the start/finish at the Pelican Point picnic shelter. Registration includes park..