Trail Running calendar near Marble 2025-2026

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 ultra running event held in Como, Colorado, at an average elevation above 10,000 feet. The event features multiple distances including 10-Mile, 19-Mile, 60k, 50-Mile, 100k, and 100-Mile races, with the 100-Mile an..

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 Ouray 100 Mile Endurance Run is a challenging ultramarathon held in Ouray, Colorado, nestled in the scenic San Juan Mountains. Covering 100 miles with an elevation gain of approximately 41,862 feet, the course features fourteen significant climbs, including a final 5,000-foot ascent to the Bridg..

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 Powderhorn Mountain Ultra and Vert Challenge, held at Powderhorn Mountain Resort in Mesa, Colorado, is a demanding mountain running event featuring two main race options: a 12-hour or 6-hour ultra on a 10K loop with approximately 1,546 feet of elevation gain per lap, and a Vertical Challenge foc..

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 200-mile loop traversing stunning hiking trails, recreation paths, forest roads, and some pavement, with elevations ranging from over 9,000 feet to peaks near 12,800 feet. Runn..

The Aspen Backcountry Marathon, hosted by Aravaipa Running in Aspen, Colorado, offers three trail running distances: a 50K ultra, a marathon, and a heavy half-marathon. The courses run almost entirely on dirt trails featuring diverse terrain with challenging ascents and descents, and significant ele..

The Sheep Mountain Ultras, part of the Human Potential Running Series, is a challenging trail running event held annually in Fairplay, Colorado. The race offers three distances: a 50-mile ultra, a 50k, and a half marathon, all starting and finishing at the Town of Fairplay Beach. Set at an average e..

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 High Five 100 is an extreme ultra-endurance running challenge held in Lake City, Colorado. Covering an estimated 90 to 105 miles with over 40,000 feet of elevation gain, the course requires runners to summit five 14,000-foot peaks and six 13,000-foot peaks in the rugged San Juan Mountains. Parti..

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 trail running event held in New Castle, Colorado, featuring distances of 3.5K, 7.7K, and a challenging 13K course. The race takes participants through beautiful mountain trails, crossing streams and winding through Aspen groves in the Flat Tops area. It offers..

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 the Arrowhead area near Edwards, Colorado, within the Vail Recreation District. The half marathon covers approximately 13.7 miles with nearly 3,000 feet of elevation gain, traversing trails across Arrowhead, Bachelor Gulch, and..