Trail Running calendar near Aurora 2025-2026

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 & 25 Mile Trail Races, held at Lory State Park and Horsetooth Mountain Park near Fort Collins, Colorado, offer challenging and scenic trail running experiences. Participants can choose between a 25-mile loop with 5,500 feet of elevation gain or a 50-mile race that doubles the distan..

The Valkyrie Trail Race, held in Cheyenne Mountain State Park near Colorado Springs, Colorado, is a women-focused trail running event offering distances from 4 miles up to 50 kilometers. The course begins on crushed limestone meadows before transitioning to singletrack trails ascending Cheyenne Moun..

The Ram Party Trail Runs is a multi-distance trail running event held at Rampart Reservoir near Woodland Park, Colorado, on May 17, 2025. It offers races ranging from 15K to 55 miles, featuring scenic courses with stunning views of Pikes Peak and the Front Range. The courses include point-to-point a..

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..

Samson's Revenge is a trail running event held at the YMCA of the Rockies in Estes Park, Colorado, honoring Samson, the famous elk of the Rockies. The race offers three distances: 10K, 27K, and 55K, featuring fast single-track trails with significant elevation gain, including a challenging ascent of..

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 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 Reuter-Hess Trail Incline is a challenging 10k trail race held in Parker, Colorado, featuring about 600 feet of elevation gain. The course begins with a lollipop loop that includes a steep incline with widely spaced stairs, making running difficult. After the incline, runners navigate rolling te..

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 Crazy Legs 10k+ Trail Run takes place at Devil’s Backbone Open Space in Loveland, Colorado. The course features a scenic loop through Hidden Valley, Hunter Loop, Laughing Horse Loop, and Wild Loop trails, covering over 10 kilometers with minimal overlap to prevent congestion. Marked by flour arr..

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, massive Pikes Peak granite rocks, and stunning mountain views. The race uses a smooth..

The Garden of the Gods Ten Mile Run® is a premier running event held in Colorado Springs, featuring a challenging 10-mile course that winds through the stunning sandstone rock formations of Garden of the Gods Park. Celebrated for over 45 years, this race attracts participants from across the United..

The Summits Trail Runs, part of the Human Potential Running Series, is an exciting trail running event set in the stunning Rocky Mountains at Granby Ranch Resort, Colorado. Scheduled for June 14, 2025, the event features various race distances, including a challenging 43-mile Quad, a 27-mile Triple,..

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 Estes Park Backyard Ultra is an endurance running event held along the scenic Lake Estes, supporting Childcare and Family Services. Participants run a 4.252-mile course on a paved bike trail, completing a lap every hour until only one runner remains. The race features no predetermined end time,..

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..