Cirque Series - Arapahoe Basin

Summer Predictor SERIES - Derek Lindstrom is a fundraising running series featuring prediction games tied to two summer races. For 2025, events take place in Leadville, Colorado, and Marquette, Michigan, with the Leadville Trail Marathon (26.2 miles) and the Marquette Half Marathon (13.1 miles). Par..

Devil on the Divide is a trail ultramarathon held in Empire, Colorado, offering two distances: 50K and 22K. The 100% dirt, point-to-point courses traverse stunning, remote terrain with views of Clear Creek County and the Continental Divide, reaching elevations above 13,000 feet. The 50K features abo..

The Breckenridge Oktoberfest 5K is a festive trail run held in historic downtown Breckenridge, Colorado, as part of the annual Oktoberfest celebration. Scheduled for Saturday, September 13, 2025, the 5K course winds through the scenic Town of Breckenridge Trails, showcasing beautiful fall foliage an..

Silverheels Trail Runs, the 12th annual event from the Human Potential Running Series, unfolds in Colorado, with races including 100k, 100-Mile, 50-Mile, 60k, 19-Mile, and 10-Mile. The revamped format places the main event at the Como Roundhouse in Como, CO, while the 100-Mile and 100k start at Burn..

The Summit 200 is a single, non-repetitive 200‑mile loop around Summit County, Colorado, centered near Frisco. The mostly non-urban route uses single-track trails, forest roads, and some rec paths and pavement, with the lowest altitude above 9,000 ft and sections climbing toward 12,800 ft, plus 12 f..

Sheep Mountain Trail Runs, part of the Human Potential Running Series, takes place near Fairplay, Colorado on the western slope of the South Park Valley. The 12th annual event offers 50-mile, 50k, and Half Marathon distances, with a 16-hour time limit and a 300-runner cap. The start/finish is at the..