Trail Running calendar near Weld County 2025-2026

The Barr Lake Trail Race, held annually in Brighton, Colorado, offers a scenic and fast trail running experience around Barr Lake State Park. Celebrating its sixth year, the event features multiple distances: 50K, 30K, half marathon, 15K, and 5K, all on flat, dirt terrain with minimal elevation gain..

Estes Park's Backyard Ultra is a unique ultramarathon held in Estes Park, Colorado, featuring scenic views of Lake Estes. Participants run a 4.252-mile loop on a paved bike trail with a 150-foot elevation gain per lap at 7,522 feet elevation. The race follows the Backyard Ultra format, where runners..

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 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..

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, running loops of approximately 10.3 miles on mostly dirt trails with..

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 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 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 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 through local trails. The event fosters camaraderie a..

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 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 Westminster Night Trail, held in Westminster, Colorado, is a vibrant night trail running event set around scenic Standley Lake. Celebrating its 12th year, the race offers multiple distances: 50K, 35K, half marathon, 10K, and 5K, all on 100% packed dirt trails featuring a mix of single-track and..

The Antelope Dash is a trail running event held at Curt Gowdy State Park near Cheyenne, Wyoming. It features 4-mile and 8-mile races that traverse rolling hills and winding trails through a scenic landscape of aspens, pines, reservoirs, streams, granite rock formations, and hoodoos. The course start..

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..

Front Range Ultra Dayze is an ultra-running festival held in Loveland, Colorado, featuring a variety of ultra-distance events including 50k, 100-mile, 200-mile, and timed races from 12 to 100 hours. The course is a flat, fast 2-mile loop with 80% dirt trail and 20% pavement, set in Centennial Park a..

The American Heroes Run, held in Longmont, Colorado, honors the memory of 9/11 with a variety of race distances on a flat, fast 1.05-mile loop course. Events include a 100-mile ultra with a 30-hour cutoff, a 24-hour run, a marathon, half-marathon, 9.11-mile run, 5K, and unique timed runs reflecting..

The Black Squirrel Half Marathon is a 13.5-mile trail race held in Lory State Park near Fort Collins, Colorado. Featuring approximately 2,000 feet of elevation gain and loss, the course offers a scenic perimeter tour of the park with stunning views of Horsetooth Reservoir, Fort Collins, the Great Pl..

The HRCA Wildcat Mountain Trail Races, scheduled for September 6, 2025, in Littleton, Colorado, features a variety of events including a 10K, 10M, and a Kid's Race. The race begins at the Douglas County East/West trailhead and takes participants through the scenic HRCA Backcountry Wilderness Area. R..