Trail Running calendar near Nederland 2025-2026

The Greenland Trail Races, set in southern Douglas County, Colorado, features a variety of running events including a 50K ultramarathon, 25K, 8M, and 4M races. Participants can enjoy scenic trails with Pikes Peak as a backdrop, aiming for personal bests on soft dirt paths. The event includes chip ti..

Niwot's Challenge is a demanding ultramarathon held in Colorado's Front Range, inspired by the Barkley Marathons. This grassroots event, limited to 40 participants, emphasizes navigation skills as runners traverse mostly off-trail terrain using only a map and compass. The challenge includes various..

The Mountain Ridge Trail Race, taking place on May 10, 2025, in Highlands Ranch, Colorado, offers a variety of distances for trail running enthusiasts, including a 21-mile, half marathon, 10K, and 5K. Celebrating its 11th year, the race features scenic dirt and single-track trails with manageable el..

The Quad Rock 50 and 25 Mile Trail Races, organized by Gnar Runners, will take place on May 10, 2025, in Lory State Park and Horsetooth Mountain Park, near Fort Collins, Colorado. This challenging event features a scenic course with significant elevation gains—over 5,500 feet for the 25-mile race an..

Samson's Revenge is a trail running event held in Estes Park, Colorado, featuring 55k, 27k, and 10k races. The course is a fast single-track trail with significant elevation gain, including a notable ascent at Bible Point. Runners will start and finish at the YMCA of the Rockies, running on Samson's..

The Endure Trail Runs, organized by the Human Potential Running Series, takes place at Mueller State Park in Divide, Colorado. This unique event features a variety of races, including a 10k, Half Marathon, and timed challenges of 12 and 24 hours. Participants in the 12-Hour and 24-Hour events will d..

The Dynafit Boneyard Boogie 5K/13K will take place in Eagle on Saturday 17 May 2025. You can run between 6 and 14 kilometers.

The Weld Your Mettle Running Festival is a four-day event taking place in Eaton, Colorado, from May 23 to May 26, 2025. It offers a variety of running challenges suitable for all levels, including a 7K run, ruck, and timed events ranging from 3 to 48 hours, either solo or as part of a relay team. Pa..

The Ol' College Try 24 Hour Ultra is Denver's inaugural 24-hour ultra race, organized by Rise Again Running Events in collaboration with Tall Tales Ranch. Scheduled for May 24-25, 2025, at Auraria Campus, this event invites runners of all abilities to challenge themselves in a non-stop race, fosteri..

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 Reuter-Hess Trail Incline is a unique running event held in Parker, Colorado, featuring a challenging 10k course and a 1-mile kids' race. The race employs a handicap start system, allowing participants of varying ages and genders to compete on an equal footing. The course includes a steep inclin..

The Leadville Turquoise Lake 20K is a scenic running event set around the picturesque Turquoise Lake in Leadville, Colorado. Participants will experience breathtaking mountain views as they navigate a course that combines 6.5 miles of hilly paved roads with 5.5 miles of single-track dirt trails. The..

The Luna (Latino Ultra Nature Adventure) is an inclusive, culturally relevant ultra running event held in Boulder, Colorado. Now in its third year, it offers various race distances, including 5km, 7 miles, 15 miles, and a marathon, all taking place on May 31, 2025. The event emphasizes human-nature..

The North Fork 50 Mile and 50K ultramarathon takes place in the scenic Colorado mountains near Buffalo Creek. The course features nearly all singletrack trails, with some double track sections, traversing diverse landscapes including burn areas from a 1996 fire, ponderosa pines, and granite rock for..

The Fish Hatchery 5K Trail Run is an exciting running event set in the picturesque surroundings of the Leadville National Fish Hatchery in Colorado. Participants will enjoy a scenic cross-country course that meanders through subalpine forests and alongside the Evergreen Lakes and lower Rock Creek ar..

The Crazy Legs 10k+ Trail Run is an exciting running event taking place at Devil’s Backbone Open Space in Loveland, Colorado. Scheduled for June 1, 2025, this trail run offers participants a challenging course marked by flour arrows, with hydration stations provided along the route. Runners can enjo..

The Vail Ultra Benefiting 50 For The Fallen is a challenging 50-mile running event set to take place at Golden Peak in Vail, Colorado. This event aims to honor and support the 50 For The Fallen organization, which focuses on providing assistance to families of fallen service members. Participants ca..

The adidas Terrex Après 5K Trail Run is an exciting event that kicks off the GoPro Mountain Games weekend in Vail, Colorado. Participants can enjoy a scenic evening run on the trails of Vail Mountain, starting and finishing at Nature Valley Mountain Plaza. The 5K course is designed to be accessible..

The Great Divide Ultra is a trail running festival held in Divide, Colorado, featuring multiple race distances including 100 miles, 100K, 50K, and 25K. The event takes place entirely within Mueller State Park, offering scenic views of Colorado’s mountains, rolling meadows, and granite rocks. The cou..

The adidas Terrex 10K Spring Runoff is an exhilarating trail running event set in the stunning Vail Valley, taking place at an elevation of over 8,000 feet. Participants will face a challenging course featuring constant elevation changes and diverse terrain, making it one of the most demanding 10K r..