Trail Running calendar near Longmont 2025-2026

The Jelm Mountain Run, held in Southeast Wyoming near Jelm, offers two challenging distances: a 10+ mile out-and-back course and a 50k race consisting of three laps of the 10-mile route. The course features rugged jeep roads with over 2,000 feet of elevation gain, starting at 7,600 feet and climbing..

The Frederick Pack Burro Race will take place in Frederick on Saturday 20 September 2025. You can run between 6 and 10 kilometers.

The Red Feather Trail Jamboree is a three-day trail running event held at Ben Delatour Scout Ranch in Red Feather Lakes, Colorado. Scheduled for September 26-28, 2025, it offers three race distances: a 50-mile ultra with 8,500 feet of elevation gain, a 50K with 4,200 feet gain, and a half marathon f..

The 24 Hours of Palmer Lake is an endurance running event held in Palmer Lake, Colorado, featuring a 24-hour race on a scenic 0.82-mile loop course atop the Palmer Divide at 7,240 feet elevation. Surrounded by mountains, the race offers a community-driven atmosphere focused on pushing mental and phy..

The Castle Rock Trail Festival, held in Castle Rock, Colorado, offers a variety of trail running events on the scenic ridgeline trails of Philip S. Miller Park and Ridgeline Open Space. Distances include a 5K, 10K, half marathon, and an ultra-distance 50K, catering to runners of all levels.Families..

The Bear Chase Race Endurance Festival is a trail running event held at Bear Creek Lake Park in Lakewood, Colorado. It offers multiple distances including 100K, 50 Mile, 50K, Half Marathon, 10K (Baby Bear), and 5K, catering especially to first-time ultramarathoners and trail runners. The course feat..

Rocky's Backyard Ultra is a unique ultra trail race held at the YMCA of the Rockies in Estes Park, Colorado, known as the highest organized Backyard Ultra in the world. Runners complete 4.167-mile laps on a challenging singletrack course featuring about 500 feet of elevation gain and loss per lap, w..

The Suffer Better Fall Trail Run is an annual mountain endurance event held at Staunton State Park, Colorado. The 9th edition, scheduled for October 11, 2025, features challenging courses including 50K and 25K distances, a unique 25K Fishslappers division involving fish catching, and a new 5K race...

The Great Trailhead Foot Race 10 Miler takes place at Bear Creek Lake Park in Lakewood, Colorado, offering runners a scenic trail experience with single-track dirt paths against the backdrop of Denver’s skyline. Participants can choose between a 5-mile or a challenging 10-mile double-lap course. Reg..

The Indian Creek Trail Runs, part of the Human Potential Running Series, is an annual fall trail running event held at Indian Creek Campground in Sedalia, Colorado. Celebrating its 12th year, it offers multiple race distances: 5-Mile, 15-Mile, 55k, and 50-Mile, with time limits of 12 to 14 hours dep..

The Blue Sky Trail Marathon & Half, held in October 2025 near Fort Collins, Colorado, offers challenging trail races through the scenic eastern hogbacks of Northern Colorado’s Front Range. The marathon covers 26.7 miles with 3,500 feet of elevation gain, while the half marathon spans 13.4 miles with..

Beware The Bear Trail Races take place at Bear Creek Lake Park in Lakewood, Colorado, offering 5km, 15km, and a combined 5+15km double race, along with a 1km kids' run. The courses feature mostly dirt trails with a mix of single and double tracks, incorporating short steep hills, rollers, and varied..

The Colorado 24 Hour Run will take place in Windsor from Saturday 1 November 2025 to Sunday 2 November 2025. You can run between 6 and 24 kilometers.

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..

The Bingo! Trail Party is an annual trail running event held at May Farms in Byers, Colorado. Designed as a fun, community-focused "Trail Party," it offers five levels of challenge ranging from 6 to 62 miles. Runners complete loops on a mostly flat course featuring single and double track trails and..

The HRCA Backcountry Wilderness Half Marathon will take place in Highlands Ranch on Saturday 8 November 2025. You can run 13 miles.

The Louisville Trail Race, held annually in Louisville, Colorado, features a Half Marathon, 10K, and 5K, attracting runners to the scenic front range trails. The courses primarily consist of dirt trails with some bike paths, offering mostly flat terrain with challenging hills that provide stunning v..

The Thumbs Up Vertical Challenge is an 8-hour ascent race held in Estes Park, Colorado, on the Thumb Open Space trail. Participants repeatedly run a 1 km out-and-back course with a 540-foot elevation gain per ascent. Runners collect poker chips at the turnaround point to track their completed ascent..

The Sawmill Trail Runs is an annual trail running event held at Staunton State Park in Pine, Colorado, approximately 40 miles southwest of Denver. The race offers three distance options: 8-Mile, 16-Mile, and 50k, with a combined runner capacity of 250. The course features scenic and challenging terr..

The USCSA Cross Country Ski Racing Festival, held at Snow Mountain Ranch Nordic Center in Granby, Colorado, is a vibrant collegiate and junior skiing event scheduled for January 24-25, 2026. It features classic races of 15 km and 7.5 km for college and independent high school athletes, alongside CHS..