Trail Running Calendar Colorado 2025-2026

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 above 10,000 feet, the course features technical rocky climbs, fast forest single track, alpine..

The Pikes Peak Ultra is a 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. The terrain..

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 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 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 gain, reaching ove..

The Kennebec Mountain Run is a challenging 15-mile trail race held in the La Plata Mountains near Durango, Colorado. The course features a rugged alpine terrain with 3,100 feet of elevation gain, reaching over 12,000 feet at Kennebec Pass. Runners enjoy stunning views of the Animas and Dolores River..

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 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 a trail running event held at Lory State Park in Bellvue, Colorado. Scheduled for August 5, 2025, it is the first race in a four-race midweek summer trail series designed for both new and experienced trail runners. The 5K course is noted for being the fastest and flattest of..

The Lory Summer Trail Series is a welcoming midweek trail running event held every Tuesday in August at Lory State Park, Fort Collins, Colorado. It features four races with distances ranging from 5K to 12K, designed to accommodate both new trail runners and experienced racers seeking to improve spee..

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 Escape 5K Trail Run takes place at YMCA Camp Jackson in Rye, Colorado, offering participants a challenging 5K run or walk through rugged terrain with over 1,000 feet of elevation gain. The course features wild twists and turns, providing stunning views of Rye and an immersive experience in the S..

Dirt Circus - Boulder is a free community running event held in Boulder, Colorado, celebrating local trail running culture. Organized by UltraSignup, the event features a social group run with options of a casual 4.5-mile or 10K route through the local trails. Beyond running, the festival offers foo..

The Holy COW Trail Stampede is a trail running event held in Westminster, Colorado, featuring distances including a 5K and a 10-mile race. Participants enjoy a fun, community-focused atmosphere with a western theme, running through scenic trails near the Westminster Promenade Terrace. All runners re..

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 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..

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..