Trail Running Calendar Colorado 2025-2026

The Never Summer 100km and 60km trail races take place in State Forest State Park, Colorado, between the Never Summer Mountains near Rocky Mountain National Park and the Medicine Bow Mountains north of Cameron Pass. The event offers ultra-distance mountain running with challenging terrain including..

The Box Canyon Trail Races in Telluride, Colorado, offer two challenging and scenic mountain runs: a 30K and a 10-mile race. The 30K is a tough loop featuring about 5,800 feet of elevation gain, passing landmarks like Bridal Veil Falls and the Smuggler-Union Hydroelectric Plant, reaching a high poin..

The Pikes Peak Ultra is a premier trail running event held in Colorado Springs, Colorado, showcasing some of the area's best trails. Starting at Bear Creek Regional Park, the course ascends High Drive and passes through Cheyenne Canon, including the iconic Seven Bridges Trail and Pipeline Trail. Run..

The Creede 100 is a challenging 100-mile ultramarathon held in Creede, Colorado, a historic mining town. The race features a scenic and rugged course through the San Juan Mountains, climbing above 12,000 feet and traversing the Continental Divide for 25 miles. Runners experience breathtaking views,..

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 Elevation Run/Walk is an annual event held in Conifer, Colorado, featuring race distances of 10 miles, 5 miles, and 2 miles. Set at an average elevation of 8,200 feet, the course showcases the scenic Aspen Park neighborhoods, combining paved roads, dirt roads, and trail running. The event suppor..

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

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 entirely on dirt trails featuring diverse terrain with challenging ascents, descents, and significant elevation gains, reaching ov..

The Sheep Mountain Trail Runs, part of the Human Potential Running Series, is an annual trail running event held in Fairplay, Colorado. The 11th edition offers three race distances: a 50-mile ultra, a 50k, and a half marathon, all starting and finishing at the Town of Fairplay Beach. The course chal..

The Boulder Rez Marathon, held at Boulder Reservoir in Boulder, Colorado, offers a scenic and mostly flat course with only 200 feet of elevation gain. Runners enjoy trails and dirt roads alongside the reservoir, with stunning views of the water and the Rocky Mountains. The event features multiple di..

The Kennebec Mountain Run is a challenging 15-mile trail race set in the picturesque La Plata Mountains of southwest Colorado. Participants will navigate a rugged course featuring a significant elevation gain of 3,100 feet, reaching a peak of 12,200 feet at Kennebec Pass. The event promises breathta..

The Emerald Mountain Epic will take place in Steamboat Springs from Saturday 2 August 2025 to Sunday 3 August 2025.

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 Eltuck Valley 5K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 5, 2025, this event is designed to cater to both novice and experienced runners, offering a flat and fast course ideal for those looking to improve their speed. Particip..

The Lory Summer Trail Series is a fun, low-key trail running event held each Tuesday evening in August at Lory State Park, Fort Collins, Colorado. It features a series of shorter races with distances ranging from 5K to 12K, designed to welcome new trail runners and help experienced racers sharpen th..

The High Five 100 is an extreme ultra-endurance running challenge held in Lake City, Colorado. Covering approximately 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 within 48 hours. Unlike traditional ra..

The Holy COW Trail Stampede is an exciting running event held in Westminster, Colorado, featuring a 10-mile race and 5K/10K options. Participants can enjoy a fun and festive atmosphere while supporting the charity partner, Growing Home, which focuses on breaking the cycle of poverty for families in..

Dirt Circus - Boulder is a free community running event held in Boulder, Colorado, celebrating local trail running culture. Organized by UltraSignup, this one-day festival features a social group run with options of a casual 4.5-mile or 10K route, allowing runners to connect with the local running c..

Pyro's Push It Up Trail Run is an annual trail running event held in New Castle, Colorado, set in the scenic Flat Tops Wilderness. The race offers three distances: a family-friendly 3.5K, a more challenging 7.7K, and a demanding 13K "Double Down" course featuring steep, rugged terrain. Participants..

The Run The Rockies Trail Race in Frisco, Colorado, offers 5k, 10k, and half marathon distances along scenic trails on the Frisco Peninsula. The course features single track and dirt road trails with stunning views of Dillon Reservoir and the Ten Mile Range. Starting and finishing at the Frisco Nord..