Trail Running Calendar Colorado 2025-2026

The San Juan Solstice 50 Mile is a challenging ultramarathon held annually near Lake City, Colorado, typically around the summer solstice in June. Established in 1995, the race covers a 50-mile course through high mountain terrain, including snowfields and creek crossings on the Continental Divide...

The Howelsen Hill Trail Run is a challenging trail race held in Steamboat Springs, Colorado, on the scenic single-track trails of historic Howelsen Hill and Emerald Mountain. Participants can choose between 8-mile and 4-mile distances, running through beautiful terrain featuring abundant aspen trees..

Estes Park's Backyard Ultra is a unique ultramarathon held in Estes Park, Colorado, featuring scenic views of Lake Estes. Participants run a 4.252-mile loop on a paved bike trail with a 150-foot elevation gain per lap at 7,522 feet elevation. The race follows the Backyard Ultra format, where runners..

Ring the Springs is a trail running event held in Colorado Springs, Colorado, starting and finishing at Rock Ledge Ranch in the iconic Garden of the Gods. The race offers three distances: 100K, 50K, and 35K, each featuring challenging terrain with significant elevation gains and stunning natural sce..

The Sunset Trail Running Festival, taking place in Gold Hill, Colorado, features a variety of trail races including a 28K, 12K, 5K, and a Kids 1K. This event, organized by The Boulder Watershed Collective and T.E.A.M Boulder, aims to raise funds for wildfire preparation and community resilience init..

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 John Cappis is a challenging 50K mountaineering event held near Silverton, Colorado, featuring approximately 19,000 feet of elevation gain across rugged terrain. Participants summit several peaks around Silverton on an unmarked, mostly off-trail course with elevations ranging from 9,300 to 13,30..

The Timberview Trail Run is an annual trail running event held at Lory State Park in Bellvue, Colorado. Celebrating its sixth year in 2025, the race offers three distances: 5K, 5 mile, and 10 mile, catering to all levels from beginners to experienced trail runners. The scenic courses feature foothil..

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 Hahns Peak Vertical Trail Race is an 8-mile out-and-back trail run held annually at the Quarry Lot near Hahns Peak Village in Clark, Colorado. Established in 2017, the challenging course ascends 2,200 feet over 4 miles to the summit of Hahns Peak, an extinct volcano with an elevation of 10,839 f..

The Alma Foundation Race in the Clouds Dirt Festival is an exciting outdoor event taking place in Alma, Colorado, from July 10 to July 13, 2025. Set at an elevation of 10,600 feet, the festival features a variety of activities including mountain bike racing, trail running, a free kids' race, and an..

The Silverheels Trail Runs, hosted by the Human Potential Running Series, is a premier ultra running event held in Como, Colorado, featuring races at high elevations averaging over 10,000 feet. The event offers multiple distances including 10-mile, 19-mile, 60k, 50-mile, 100k, and 100-mile races. Th..

Chase the Moon is a unique 12-hour endurance running event held in Highlands Ranch, Colorado, within the scenic Highlands Ranch Backcountry trail system. Participants can compete solo or as part of 3-person or 5-person relay teams, running loops of approximately 10.3 miles on mostly dirt trails with..

The Hardrock 100 is a challenging 100-mile ultramarathon held annually in the San Juan Mountain Range of southwestern Colorado. The race features a grueling 66,394 feet of total elevation change, with an average altitude of over 11,000 feet, ranging from 7,680 feet in Ouray to 14,048 feet atop Handi..

The Grin & Bear It is Crested Butte’s oldest trail challenge, held in Crested Butte, Colorado. The event features two main running races: a traditional 15 km out-and-back course and a 25 km loop course, both starting and finishing at the Crested Butte Nordic Center. The 25 km loop includes significa..

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 Royal Gorge Whitewater Festival, held annually in Centennial Park, Cañon City, Colorado, is a vibrant celebration of whitewater sports and outdoor activities. The 16th edition features a variety of events including whitewater competitions, trail runs, and mountain bike rides suitable for all exp..

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 High Lonesome 100 is a challenging 100-mile trail race set in the stunning Sawatch Range of the Colorado Rocky Mountains. Participants will experience a grueling course featuring 23,500 feet of vertical gain, reaching elevations of 13,100 feet. The race includes a loop that traverses beautiful s..