Barr Lake 30k and 15k

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..

The Bear Chase Race Endurance Festival unfolds at Bear Creek Lake Park in Lakewood, Colorado, and offers six races: 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K (with a Baby Bear 10K variant). The mostly dirt, single-track course is described as fast by trail standards and not overly technical, wi..

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 takes place at Bear Creek Lake Park in Lakewood, Colorado, with 5- and 10-mile trail options. Runners tackle single-track and dirt trails in the shadow of Denver's skyline, with the 10-mile course as a double lap to the finish line party. Start and finish are at the Pel..

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..

Louisville Trail Race in Louisville, Colorado offers Half Marathon (13.1 miles), 10K (6.2 miles), and 5K (3.1 miles) on mostly dirt trails through the Front Range backdrop near the Flat Irons. The mostly flat to gently rolling course features two notable climbs and panoramic views of the Front Range..