Trail Running Calendar Colorado 2025-2026

The Castle Rock Trail Festival / liveBIG Run is a trail running and walking event on the Ridgeline trail system in Castle Rock, using Philip S. Miller Park and Ridgeline Open Space. The event includes a family obstacle run for children ages 5 to 12 and longer trail races for adult participants. Par..

The Rim to Rim Royal Gorge Races, held in Canon City, Colorado, offer a scenic and challenging running experience featuring three main events: a 5K road run, an 8-mile trail run, and a half marathon trail run. Each race includes the unique opportunity to cross the iconic Royal Gorge Bridge, the high..

Hanging Flume 50k is an ultrarunning trail race in Uravan, Colorado, starting and finishing at the historic Uravan Ballpark. The 50-kilometer course forms a large loop that mostly follows old mining two-track and remote desert single-track, threading canyons, slick-rock, and expansive southwestern v..

The Above the Clouds Ultra is an annual trail running event held in Woodland Park, Colorado, known as the "City Above the Clouds." It features two race distances: a 50K ultra and a 10K. The course showcases stunning Colorado fall colors and offers fast, flowing singletrack trails around Rampart Rese..

The West Elk Challenge Trail Marathon takes place on October 4, 2025, in the North Fork Valley of Colorado. It is a point-to-point trail race that starts at Crawford Reservoir State Park and finishes in the town of Paonia along the North Fork of the Gunnison River. The event is a fundraiser for the..

Rocky’s Backyard Ultra is held at the YMCA of the Rockies Estes Park Center in Estes Park, Colorado. Runners must complete 4.167 miles in under one hour each lap, with the field reduced to a single finisher as the race continues until no others remain. The course loops around the boundary of RMNP on..

The Bear Chase Race Endurance Festival occurs at Bear Creek Lake Park in Lakewood, Colorado, offering 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K (plus the Baby Bear 10K). The mostly dirt, single-track course is described as fast by trail/ultra standards and rewards sweeping mountain views with c..

Sage Burner Trail Race is held at Hartman Rocks Recreation Area in Gunnison, Colorado. The event date is Saturday, October 11, 2025. Distances offered include: 50K 28K 15K The event location features high desert terrain with sage brush and 360 degree views of the Maroon Bells, the San Juan Mounta..

Boulder XC Series Meet 1 is a family-friendly cross-country event held at Valmont City Park (South) in Boulder, Colorado (5110 Valmont Rd). The meet offers three distances: 1K for younger runners, 3K for those up to 16, and a 5K open race, welcoming participants of all ages and abilities. It’s the f..

Rubey Rescue Run is a 5K uphill trail race held in Aspen, Colorado. The course climbs Buttermilk Mountain, starting near the base at Buttermilk Mountain Lodge and gaining about 1,700 feet to the Cliff House, offering a timed competition and sweeping views of the Maroon Bells. Participants may run wi..

The Chicken Creek Challenge is a cross-country running event held in Mancos, Colorado, featuring races for middle and high school athletes. Middle school participants compete in 3.5-kilometer races, while high school runners tackle 5-kilometer courses. The event includes multiple categories such as..

Suffer Better Fall Trail Runs take place at Staunton State Park, just off Highway 285 near Conifer, Colorado. The event offers four distances: 50K, 25K, a 25K FishSlappers edition, and a new 5K. The course showcases CO’s best trails—lovely, flowing singletrack with significant vertical gain (roughly..

The Great Trailhead Foot Race 5 & 10 Miler is a trail-running event held at Bear Creek Lake Park in Lakewood, Colorado. Runners choose a 5-mile course or a 10-mile option (two laps) on single-track and dirt trails, with the start/finish at the Pelican Point picnic shelter. Registration includes park..

The Bobcat Trail Race takes place on Saturday, October 18, 2025, at Palmer Park in Colorado Springs, CO (3650 Maizeland Rd). The event offers multiple trail distances: 50K (about 31.0 miles) 25K (about 15.3 miles) 10K (about 6.4 miles) 5K (about 3.7 miles) The races use Palmer Park’s trail system..

Indian Creek Trail Runs, the oldest official race in the Human Potential Running Series, is held at Indian Creek Campground in Sedalia, Colorado. The 12th annual Fall Classic offers four distances — 5-Mile, 15-Mile, 55k, and 50-Mile — with a combined cap of 225 runners. Runners traverse seldom-used..

The Blue Sky Marathon & Half takes place October 18-19, 2025 on trails between Horsetooth Mountain Park and Devil’s Backbone Open Space in Fort Collins, Colorado. Distances offered: 26.7 miles (3,500 ft elevation gain/loss) 13.4 miles (1,800 ft elevation gain/loss) Course elevations range fro..

Beware The Bear Trail Races take place at Bear Creek Lake Park in Lakewood, Colorado. Organizers offer four options: a 5K, a 15K, a 5K+15K Double, and a Kids 1K. The mostly dirt courses feature single and double-track trails with short, steep climbs, rollers, and mixed terrain designed as a friendly..

Bridge Burner Ultra takes place in Canon City, Colorado. The event offers multiple distances—35 miles, 50K, 35K, and 10K—on a single-loop course. Runners follow the Arkansas River along Tunnel Drive, passing granite tunnels, then ascend to 7,109 feet for expansive views of Royal Gorge, the Sangre de..

Hosted in Fort Collins, Colorado, the Colorado 24 Hour Run offers 24-hour, 12-hour, and 6-hour events, including relays, on a single 1-mile dirt loop. The course is described as Colorado’s most scenic flat dirt loop—fully supported and easy on feet and eyes. Runners can tackle distances individually..

The Colleen De Reuck XC Classic is a cross country running event held annually at Harlow Platts Community Park in Boulder, Colorado. Honoring renowned distance runner Colleen De Reuck, the race promotes health, fitness, and celebrates local Olympians, with 2025 honoring 2012 Olympic marathoner Yoshi..