Trail Running Calendar Colorado 2025-2026

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..

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 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..

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 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 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 ultramarathon held in Vail, Colorado, starting at The Hangout at Golden Peak. This challenging mountain race offers participants a scenic and demanding course through the stunning terrain of Vail. The event supports the 50 For The Fallen organ..

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 event held in Divide, Colorado, featuring distances of 100 miles, 100k, 50k, and 25k. Set in the scenic Mueller State Park, the course showcases spring-fed meadows, Pikes Peak granite rock formations, and stunning mountain views. The race uses a smoo..

The Broken Brain Backyard is an ultradistance running event held at Loudy Simpson Park in Craig, Colorado. Scheduled for June 7, 2025, it features a unique backyard ultra format where participants run a 4.167-mile loop every hour on the hour until only one runner remains. The course is a rolling loo..

Mace’s Hideout 100 is a challenging and scenic 101-mile ultramarathon held in the Wet Mountains of Colorado near Beulah. The course features a dramatic elevation range from 6,608 to 11,659 feet, with a total elevation gain of 22,500 feet, averaging 9,058 feet in altitude. Runners traverse diverse ec..

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..

The San Juan Solstice 50 Mile is a challenging ultramarathon held annually near Lake City, Colorado, typically around the summer solstice in June. Established in 1995, the race covers a 50-mile course through high mountain terrain, including snowfields and creek crossings along the Continental Divid..

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 Howelsen Hill Trail Run is a challenging trail race held in Steamboat Springs, Colorado, on the scenic single-track trails of historic Howelsen Hill and Emerald Mountain. The event offers two distances: 8 miles and 4 miles, featuring a beautiful loop that includes uphill climbs on Lupine Trail a..

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..