Trail Running Calendar Colorado 2025-2026

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..

The Run The Rockies Trail Race offers a scenic running experience through the Frisco Peninsula trails, featuring a 5k, 10k, and half marathon. Participants can enjoy stunning views of Dillon Reservoir and the Ten Mile Range, making it an ideal course for both beginners and seasoned runners. The even..

Dirt Circus - Boulder is a vibrant community running event scheduled for August 9, 2025, in Boulder, Colorado. Organized by UltraSignup, this festival celebrates local races, run clubs, and businesses, fostering camaraderie among trail running enthusiasts. Participants can enjoy a social run with op..

The Into the Hills Eltuck 10K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 12, 2025, this event is designed to cater to both novice and experienced trail runners, offering a challenging course with significant elevation gain and stunni..

The San Juan Softie 100 is an ultra running event set in the stunning San Juan mountains of southwest Colorado. This challenging 100-mile race features an average elevation of nearly 10,000 feet and includes over 20,000 feet of vertical gain, making it a true test of endurance for participants. The..

The Cheyenne Mountain Run is a celebrated annual running event held at Cheyenne Mountain State Park, with the next edition scheduled for August 16, 2025, marking its 10th anniversary. Participants can choose from three race distances: 5K, 10K, and 25K. The event features cash prizes for top finisher..

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 race challenges participants with a 100-mile out-and-back course that features extreme elevation changes, reaching a peak of 1..

The Into the Hills Eltuck 5K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 19, 2025, this event features a challenging course with a steep climb and descent, making it suitable for both novice and experienced trail runners. Participants..

The NoCo Urban Ultra & Relay is a long-distance running event taking place on August 22-23, 2025, along the scenic Poudre River Trail in Northern Colorado. Participants can choose from a 50-mile solo race, a 100-mile solo race, or relay options for both distances, accommodating teams of 2 to 8 runne..

The Staunton Rocks! Marathon and Half Marathon, scheduled for August 23, 2025, takes place in the scenic Staunton State Park, located in Colorado's Front Range Mountains. This event features a challenging yet accessible course, primarily on singletrack trails, allowing participants to enjoy breathta..

The Telluride Mountain Run is an exhilarating and challenging race set in the stunning San Juan Mountains of Colorado, above the historic town of Telluride. Participants can choose from three demanding routes: 40 miles, 24 miles, and 13 miles, all featuring technical terrain that includes old mining..

The Rio Grande 100 is an exhilarating ultramarathon set in South Fork, Colorado, featuring a challenging course that traverses the stunning La Garita mountains. Runners will experience diverse terrains, from arid forests to alpine tundra, with elevations exceeding 12,000 feet. The event is known for..

The Continental Divide Trail Run, scheduled for August 23, 2025, in Steamboat Springs, Colorado, features three trail race distances: 5 Mile, 16 Mile, and 50K. Participants will experience stunning views while navigating through aspen and pine forests, with significant elevation gains—over 3,500 fee..

The Westminster Night Trail is a vibrant running event held at Standley Lake in Westminster, Colorado, celebrating its 12th year. Participants can choose from various distances, including 50K, 35K, half marathon, 10K, and 5K, all set against the stunning backdrop of the lake and surrounding mountain..

The Byers Peak Stampede Half Marathon & 5K Run is an exciting running event set in the stunning Rocky Mountains, just 60 miles from Denver. Scheduled for August 23, 2025, the event features a challenging half marathon and a 5K, catering to athletes of all levels. The courses primarily traverse dirt..

The Arrowhead Half Marathon and 5K is a scenic running event held in Arrowhead, Colorado, featuring a challenging half marathon course with 3,000 feet of elevation gain over 13 miles, and a 5K that is mostly downhill, making it accessible for all ages and abilities. The event showcases beautiful tra..

The Eltuck Valley 12K is part of the Lory Summer Trail Series, taking place at Lory State Park in Bellvue, Colorado. This event features a series of midweek trail races designed for both novice and experienced runners, offering distances from 5K to 12K. The series aims to provide a fun and low-key a..

The Front Range Ultra Dayze is an exciting ultra-running festival taking place in Loveland, Colorado, featuring 100 hours of continuous running. This event invites participants from across the U.S. to engage in various ultra-distance races, including options for 200-mile, 100-mile, and timed events..

The Grand Traverse Mountain Run is a challenging 40-mile ultra marathon that takes place from Crested Butte to Aspen, Colorado. Following the route of the Grand Traverse Backcountry Ski race, participants face over 6,000 feet of elevation gain while navigating the stunning Elk Mountains. This event..

The Creede Mountain Run, established in 1987, is a celebrated annual event held in Creede, Colorado, offering a range of race distances including 2, 12, 22 miles, and a challenging 50K. Set against the stunning backdrop of the San Juan Mountains, participants experience a scenic course that begins i..