Trail Running calendar near Denver 2025-2026

The Reuter-Hess Trail Incline is a challenging 10k trail race held in Parker, Colorado, featuring about 600 feet of climbing. The course begins with a lollipop loop that includes a steep incline with stairs spaced roughly 1.5 strides apart, making running difficult. After the incline, runners naviga..

The 3rd Latino Ultra Nature Adventure (LUNA) is a unique trail running event scheduled for May 31, 2025, in Boulder, Colorado. This culturally relevant and inclusive event features various distances, including 5km, 7 miles, 15 miles, and a marathon. LUNA aims to promote physical and mental health th..

The Leadville Turquoise Lake 20K is a scenic mountain race held in Leadville, Colorado, featuring a 20-kilometer course around Turquoise Lake. The route begins with 6.5 miles of hilly paved road, followed by 5.5 miles of single-track dirt trail, offering runners stunning views of the surrounding mou..

LUNA (Latino Ultra Nature Adventure) is an inclusive ultra running event held annually at Meyers Homestead Trailhead in Boulder, Colorado. Now in its third year, LUNA offers multiple race distances including 5km, 7 miles, 15 miles, and a marathon, accommodating up to 150 runners combined. The event..

The North Fork 50 Mile/50K is a premier ultramarathon held in Buffalo Creek, Colorado, about 50 miles southwest of Denver. The event features two distances: a 50-mile race with 6,425 feet of elevation gain and a 50K (31.1 miles) with 3,670 feet of climb. The course is 100% soft surface, primarily si..

The Fish Hatchery 5K Trail Run takes place at the historic Leadville National Fish Hatchery in Leadville, Colorado. This scenic 5K features a cross-country style course that winds through subalpine forest areas near Evergreen Lakes and lower Rock Creek. The route includes a mix of dirt roads, paths,..

The Crazy Legs 10k+ Trail Run takes place at Devil’s Backbone Open Space in Loveland, Colorado. This scenic trail race covers over 10 kilometers on a looped course featuring sections of Hidden Valley, Hunter Loop, Laughing Horse Loop, and Wild Loop trails. The course is marked with flour arrows and..

The Vail Ultra Benefiting 50 For The Fallen is a 50-mile ultra running event held at The Hangout at Golden Peak in Vail. This challenging race is part of the VVF Summer Mountain Games and supports the 50 For The Fallen organization. The event offers a competitive and inspiring atmosphere for men, wo..

The adidas Terrex Après 5K Trail Run is a spirited evening trail race held on Vail Mountain, starting and finishing at Nature Valley Mountain Plaza in Vail Village. This 5-kilometer course features diverse terrain including forest service dirt roads, rocky paths, grass, loose gravel, and undulating..

The Great Divide Ultra is a premier trail running festival held in Divide, Colorado, featuring distances of 100 miles, 100K, 50K, and 25K. Set in Mueller State Park, the course showcases stunning spring-fed meadows, Pikes Peak granite formations, and panoramic mountain views. The event offers a smoo..

The Garden of the Gods Ten Mile Run® is a premier race held in Colorado Springs, Colorado, featuring a challenging 10-mile course through the stunning 300-foot sandstone rock formations of Garden of the Gods Park, including the iconic Balanced Rock. The race also offers 10K road and trail run option..

The adidas TERREX 10K Spring Runoff is a challenging trail running event held in Vail, Colorado, at nearly 9,000 feet elevation. Participants race on the scenic Vail Mountain trails, navigating a course with constant elevation changes and diverse terrain including dirt roads, rocky paths, grass, loo..

The Summits Trail Runs, part of the Human Potential Running Series, take place at Granby Ranch Resort in Colorado's Rocky Mountains. This event offers multiple trail running distances: Single (6 miles), Double (21 miles), Triple (27 miles), and Quad (43 miles), plus a unique 32-hour Elevation Challe..

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..

Ring the Springs is a trail running event held in Colorado Springs, Colorado, starting and finishing at Rock Ledge Ranch in the iconic Garden of the Gods. The race offers three distances: 100K, 50K, and 35K, each featuring challenging terrain with significant elevation gains and stunning natural sce..

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 Midsummers Night Run is a 10K race held in Winter Park, Colorado, starting and finishing at the base of Winter Park Resort. The course features a mix of gravel roads and trails with an elevation gain of approximately 570 feet, offering a scenic and moderately challenging route. This event is par..

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..

The Leadville Trail Marathon and Heavy Half are challenging trail running events held in Leadville, Colorado, traversing historic mining district trails. The marathon covers 26.4 miles with 6,167 feet of elevation gain, while the Heavy Half is 15.4 miles with 3,421 feet of gain. Both courses reach t..