Trail Running calendar near Aspen 2025-2026

The Midsummers Night Run is a 10K race held in Winter Park, Colorado, starting and finishing at the base of Winter Park Resort. The course features a mix of gravel roads and trails with an elevation gain of approximately 570 feet, offering a scenic and moderately challenging route. This event is par..

The Leadville Trail Marathon and Heavy Half are challenging trail running events held in Leadville, Colorado, featuring rugged courses through the historic mining district. The marathon covers 26.4 miles with an elevation gain of 6,167 feet, reaching the highest point at Mosquito Pass at 13,185 feet..

The Leadville Firecracker 5K is a festive running event held in Leadville, Colorado, the highest incorporated city in North America. Participants can walk or run a 5-kilometer (3.1-mile) course that begins and ends in downtown Leadville, offering a unique high-altitude experience above 10,000 feet...

The Silverheels Trail Runs, hosted by the Human Potential Running Series, is a premier trail running event held in Como, Colorado, featuring races at an average elevation above 10,000 feet. The event offers multiple distances including 10-Mile, 19-Mile, 60k, 50-Mile, 100k, and 100-Mile ultra races...

The Grin & Bear It is Crested Butte’s oldest trail challenge, held in Crested Butte, Colorado. The event features a 25 km loop run, a traditional 15 km out-and-back run, and a new 25 km mountain bike race introduced in 2025. The courses start and finish at the Crested Butte Nordic Center, showcasing..

The Leadville Silver Rush 50M is a challenging 50-mile trail run held in Leadville, Colorado, featuring 7,503 feet of elevation gain and reaching a high point of 12,024 feet. The out-and-back course traverses historic mining roads on the east side of Leadville, offering runners stunning views of the..

The High Lonesome 100 is a challenging 100-mile trail ultramarathon held in the Sawatch Range of the Colorado Rocky Mountains, starting and finishing near Mount Princeton. The loop course features 23,500 feet of elevation gain, reaching a high point of 13,100 feet and averaging 10,600 feet in elevat..

The Audi Power of Four Trail Run is a scenic trail running event held in Aspen, Colorado, featuring routes across the mountains of Aspen Snowmass. Scheduled for July 19, 2025, the race offers three distance options: 50K, 25K, and 10K, catering to a range of trail runners. Participants experience div..

The Grand Mesa Ultras, held on the Grand Mesa in Colorado, offers mountain trail races including a 50-mile, 55K, and 30K distance. Set on the world's largest flat-topped mountain with an average elevation over 10,000 feet, the event features challenging, technical trails with rocky climbs, fast fore..

The Mountain Fair 4-Miler is a scenic running event held in Carbondale, Colorado, starting near Prince Creek Road and finishing at Sopris Park during the Mountain Fair. The 4-mile course is mostly a gentle downhill, beginning about three miles up Prince Creek Road and descending to Highway 133, then..

The Summit 200 is a challenging 200-mile mountain ultramarathon held in Summit County, Colorado. The race features a single large loop primarily on stunning hiking trails, forest roads, recreation paths, and some pavement, with elevations ranging from over 9,000 feet to nearly 13,000 feet. Participa..

The Aspen Backcountry Marathon, held in Aspen, Colorado, offers three trail running distances: a 50K ultra, a marathon, and a heavy half-marathon. The courses run almost exclusively on dirt trails featuring diverse terrain with challenging ascents, descents, and significant elevation gain, peaking a..

The Sheep Mountain Ultras, part of the Human Potential Running Series, is an annual trail running event held in Fairplay, Colorado, featuring challenging courses at an average elevation over 10,600 feet. The event offers three distances: a 50-mile ultra, a 50k, and a half marathon, catering to both..

The TransRockies Run is a renowned six-day, 120-mile stage race held in Colorado, offering an unforgettable trail running adventure through the Rocky Mountains. This multi-day event challenges participants with rugged terrain and scenic mountain landscapes, fostering a strong community atmosphere am..

The Run the Rockies Trail Race is held in Frisco, Colorado, featuring 5k, 10k, and half marathon distances. The courses traverse the scenic Frisco Peninsula trails, offering stunning views of Dillon Reservoir and the Ten Mile Range. Starting and finishing at the Frisco Nordic Center, the race includ..

Pyro's Push It Up Trail Run is a scenic mountain trail race held in New Castle, Colorado, featuring distances of 3.5K, 7.7K, and a challenging 13K course. The trail winds through Aspen groves and crosses streams in Colorado's Flat Tops, offering a family-friendly atmosphere suitable for runners and..

The Buena Vista Pack Burro Race, held in Buena Vista, Colorado, is a unique 14-mile pack burro running event and the third leg of the 2025 PBR Triple Crown. Participants race alongside their burros, donkeys equipped with pack saddles carrying prospector gear, over challenging terrain that reflects t..

The Leadville Trail 100 Mile Run, held annually in Leadville, Colorado, is a legendary ultramarathon known as the "Race Across the Sky." Established in 1983, this grueling 100-mile out-and-back course challenges runners with extreme Rocky Mountain terrain, starting at 10,200 feet and climbing to a p..

The Arrowhead Half Marathon & 5K is a scenic trail running event held in Arrowhead, Colorado, featuring challenging courses through the Arrowhead, Bachelor Gulch, and Beaver Creek Ski Resorts. The half marathon covers approximately 13.7 miles with 2,924 feet of elevation gain, offering runners breat..

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 held on dirt roads and trails with stunning mountain views. The half marathon course starts at..