Trail Running calendar near Boulder 2024-2025

The Timberview Trail Run is an exciting annual trail race held at Lory State Park in Colorado, featuring three distances: a 10-mile, a 5-mile, and a 5K. This event caters to athletes of all levels and ages, offering a scenic course with stunning views of Horsetooth Reservoir and the surrounding foot..

The Leadville Trail Marathon and Heavy Half is a challenging running event set in the historic mining district of Leadville, Colorado. Participants can choose between a 26.4-mile marathon or a 15.4-mile Heavy Half, both featuring rugged trails and high-altitude terrain, with the marathon reaching an..

The Vail Hillclimb will take place in Vail on Saturday 5 July 2025.

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' bike race, an..

Chase the Moon is an exciting overnight running event held in the Highlands Ranch Backcountry trail system, featuring a 12-hour solo ultramarathon and team relays. Participants can choose to run solo or form teams of 3 or 5. New this year, shorter distances such as 5 miles, 10 miles, 25K, and 50K ar..

The Silverheels Trail Runs, part of the Human Potential Running Series, will take place on July 11-12, 2025, in Como, Colorado. This annual event features multiple race distances, including a 100-Mile, 100k, 50-Mile, 60k, 19-Mile, and 10-Mile, catering to a variety of runners. The courses, set at an..

The Leadville Silver Rush 50M is a challenging 50-mile trail run set against the stunning backdrop of the Rocky Mountains. Participants will navigate a course featuring significant elevation gain, technical climbs, and breathtaking views, making it a true test of endurance and skill. The event serve..

The Never Summer 100km and 60km races, organized by Gnar Runners, will take place in July 2025 in the stunning Colorado Rockies. This challenging mountain race features a course that traverses diverse terrains, including high alpine ridges, meadows, and boulder fields, with significant elevation cha..

The Elevation Run/Walk is a community-focused event taking place in Conifer, Colorado, on July 26, 2025. This annual race features multiple distances, including 10 miles, 5 miles, and a 2-mile fun run, showcasing the scenic trails and neighborhoods of Conifer at an average elevation of 8,200 feet. P..

The Summit 200 is an extraordinary 200-mile mountain race set in Summit County, Colorado, featuring a challenging loop that showcases stunning hiking trails, forest roads, and scenic views. Participants will experience significant elevation changes, with the lowest point over 9,000 feet and sections..

The Sheep Mountain Ultras, part of the Human Potential Running Series, is an annual trail running event held in Fairplay, Colorado. Scheduled for August 2, 2025, it features three race distances: a challenging 50-mile, a 50k, and a half marathon, all set against the stunning backdrop of the South Pa..

The Boulder Rez Marathon is a scenic running event held at the Boulder Reservoir in Boulder, Colorado. Participants can choose from various distances, including a marathon, half marathon, 3/4 marathon, and 10K, all set along dirt roads and trails with stunning views of the reservoir and Rocky Mounta..

The Lory Summer Trail Series, scheduled for August 2025, features a series of midweek trail races at Lory State Park in Fort Collins, Colorado. Participants can choose from distances of 5K, 10K, and 12K, designed to cater to both novice and experienced trail runners. The event aims to create a fun a..

The Holy COW Trail Stampede is an exciting running event held in Westminster, Colorado, featuring a 10-mile race and a 5k/10k option. 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..

The Leadville Trail 100 Mile Run, known as the "Race Across the Sky," is a prestigious ultramarathon held annually in Leadville, Colorado. Established in 1983, this grueling event challenges participants with a 100-mile out-and-back course that features extreme elevation changes, including a peak at..

The Westminster Night Trail, celebrating its 12th year, is an exciting nighttime running event held at Standley Lake in Westminster, CO. Participants can choose from various distances, including 50K, 35K, Half Marathon, 10K, and 5K, all set against the stunning backdrop of Colorado's natural beauty...

The Front Range Ultra Dayze will take place in Loveland from Thursday 28 August 2025 to Monday 1 September 2025.

The Cirque Series at Arapahoe Basin is a thrilling mountain running event scheduled for September 6, 2025. Participants will tackle a challenging 9.4-mile course with an elevation gain of 2,411 feet, starting from the base at 10,780 feet. The route features stunning views and diverse terrain, includ..

The Snow Mountain Ranch Trail Running Festival, held at the YMCA of the Rockies in Granby, Colorado, offers a stunning celebration of trail running with multiple race options including a 50K, 33K, Half Marathon, 10K, and 5K. Participants can enjoy breathtaking views of rolling hills and vibrant fall..

The Red Feather Trail Jamboree is a three-day trail running event held in September 2025 at the Ben Delatour Scout Ranch in Red Feather Lakes, Colorado. Participants can choose from three race distances: 50 miles, 50K, and a half marathon, each featuring scenic trails with varying elevations and ter..