Trail Running Calendar Colorado 2025-2026

Welcome to Colorado's premier trail running calendar for 2025-2026! Recognized as a trail runner's haven, Colorado seamlessly blends bustling urban settings with pristine mountain terrains. Whether you're a native, a newbie, or a visitor exploring the Centennial State's running trails, our calendar ensures you don't miss out on any event.

Denver, the renowned Mile High City, beckons runners with its urban-meets-nature charm. Iconic routes like the Cherry Creek Trail zigzag right through the city's pulse. Venturing south, Colorado Springs, dubbed the "Olympic City", boasts of trails skirting the monumental Garden of the Gods. Here, a run transcends the ordinary, offering an experience akin to striking gold.

For those seeking a quiet escape, Aurora presents peaceful reservoir paths, making urban detox achievable. If the allure of academic vibes mixed with nature captivates you, Fort Collins and its famous Horsetooth Reservoir trails won't disappoint. Meanwhile, Lakewood introduces runners to nature's canvas with the Red Rocks painting every run. And let's not forget Boulder, offering a diverse range of trails set against the stunning backdrop of the Flatirons.

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 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 of athletes including beginners and children. The scenic courses wind through f..

The Leadville Trail Marathon and Heavy Half are challenging trail running events held in Leadville, Colorado, traversing historic mining district trails. The marathon covers 26.4 miles with 6,167 feet of elevation gain, while the Heavy Half is 15.4 miles with 3,421 feet of gain. Both courses reach t..

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..

July 2025

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 standing at 10,839 feet, feat..

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 a challenging 100-..

The Hardrock 100 is a challenging 100-mile ultramarathon held annually in the San Juan Mountain Range of southwestern Colorado. The race features a counter-clockwise loop course that traverses rugged backcountry terrain, including 4WD roads, dirt trails, and cross-country sections. Runners experienc..

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. The race features a 10.3-mile loop with about 870 feet of elevation..

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 altitudes up to 12,024 feet. The out-and-back course traverses historic mining roads on the east side of Leadville, offering stunning views of the Rocky M..

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..

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 approximately 41,862 feet of elevation gain, the course features fourteen major climbs, including a final 5,000-foot ascent to the Bridge of Heav..

The Spring Creek Memorial Trail Run, held in Steamboat Springs, Colorado, is a scenic trail running event featuring two distances: a challenging 9.5-mile loop and a 5K out-and-back course. The 9.5-mile race includes rugged, primitive trails with significant elevation gain (~1,750 ft in the first 4 m..

The Powderhorn Mountain Ultra and Vert Challenge, held at Powderhorn Mountain Resort in Mesa, Colorado, is a demanding trail running event set for July 19, 2025. Participants can choose between a 12-hour or 6-hour ultra race featuring a 10K loop with approximately 1,546 feet of elevation gain per la..

The Audi Power of Four Trail Run is an exciting running event set in the scenic mountains of Aspen Snowmass. Participants can choose from three different race distances: a challenging 50K, a 25K, and a 10K run, catering to various skill levels. This event not only offers a chance to enjoy the beauti..

The Silverton Alpine Marathons, held in Silverton, Colorado, offer trail running events including a 50K, marathon, and 8-mile race through the scenic San Juan Mountains. The courses follow the historic Alpine Loop jeep roads, passing ghost mining towns like Howardsville, Eureka, Animas Forks, and Gl..

The Kendall Mountain Run is a challenging mountain race held annually in Silverton, Colorado. It features two distances: a 12-mile course and an 11-kilometer course. Starting at 9,318 feet in downtown Silverton, runners ascend jeep roads to a thrilling final scramble to the summit of Kendall Mountai..

The Barr Trail Mountain Race is a historic summer mountain running event held in Manitou Springs, Colorado. The challenging 12.6-mile course starts at the Cog Railway Station (6,570 ft) and ascends the iconic Barr Trail to Barr Camp at 10,200 ft before descending to finish at the Barr Trailhead. Thi..