Trail Running calendar near Boulder 2026-2027

Join the community for a 5K run or walk on a brand new dirt course at the North Arvada Middle School Athletic Complex. Support local high school racers before taking on this off road route yourself.

A load bearing endurance event at Staunton State Park on September 5, 2026. Routes range from 6.5 to 21.5 miles with loads from 10 to 40 lb and proceeds benefit the Special Forces Foundation.

A multi-distance running event in Longmont, CO on September 11-12, 2026, held on a 1.05-mile loop. Events range from a 100-mile race with a 30-hour cutoff to shorter runs, with aid stations, timing, and finish awards.

A longstanding Nederland, Colorado running event offering a 5K road run, a 10K trail, and a trail half marathon, with family-friendly features, on-leash dogs allowed in the 5K, and costume encouragement.

A one day trail running festival at YMCA of the Rockies in Granby, Colorado on September 12, 2026 featuring 50K, 33K, half marathon, 10K and 5K on dirt and grass trails with loop formats, aid stations, drop bag access and on site lodging an..

A 13.5 mile trail half around Lory State Park near Fort Collins with about 2,000 feet of climb, marked singletrack, aid stations, and a free one mile kids race.

Trail race in Empire, Colorado on September 12, 2026 offering 50K and 22K point-to-point courses on dirt single-track with high altitude views. The 50K exceeds 13,000 feet and requires prior ultra running experience.

Trail races on Meadow Mountain in Minturn offering 11K and 5K courses on singletrack and dirt trail, with aid stations, post-race refreshments, and series awards.

A community trail race on North Table Mountain near Golden, CO, offering 10 Mile and 5 Mile courses. Organized by BeyondHome to support families moving from homelessness to self sufficiency.

A day of youth and adult cross country races in Aurora, Colorado on September 20, 2026, featuring grass courses with small undulations, a creek crossing, and bale jumps; distances run from 2k youth races up to a 5k open race.

Experience the wild spaces of Northern Colorado with a weekend of trail races ranging from a half marathon to a 50 mile ultra through scenic forests and scout camp trails. Stay on site with available camping and community meals.

A community driven 24 hour endurance race on a *0.82 mile* loop atop the Palmer Divide in Palmer Lake, Colorado. Top distance finishers receive awards and the first ten runners to reach 100 miles receive onsite buckles.

A two-day trail and bike event in Estes Park featuring 31-mile bike and run options, a 15-mile heavy half, and a 62-mile duathlon, with rugged trails, significant climbs, and aid stations supporting competitors.

A point to point trail race from Vail to Minturn with 26K and 14K courses across Vail Mountain. Both routes feature alpine singletrack, scenic views of Mt. Holy Cross, staffed aid stations and a post race lunch voucher.

A *5K* trail run on Town of Breckenridge Trails that finishes at Blue River Plaza on Main Street during Breckenridge Oktoberfest. Field limited to 300 runners; first 250 registrants receive a long-sleeve technical tee and 21+ entrants get a..

A trail run and walk at Terry Bison Ranch in Cheyenne on September 26, 2026, offering distances from a half marathon to a kids run. Proceeds support cardiac and pulmonary rehab equipment and participants receive a 2026 event T shirt and bre..

The 4th annual Greenland Open Space Pack Burro Race in Larkspur, Colorado offers 8 Mile and 3 Mile pack burro divisions. Teams must register a burro partner, follow animal welfare rules, and the field is limited to 75 participants.

A weekend of looped trail races at Bear Creek Lake Park near Lakewood CO offering 100K, 50 Mile, 50K, half marathon, 10K and 5K on mostly singletrack dirt.

Experience the scenic HRCA Backcountry Wilderness Area with trail races for the whole family. Enjoy rolling hills and open views followed by a pancake breakfast and finisher medals for all participants in Littleton.

A Woodland Park trail event featuring 50k and 10k options on singletrack and forest roads with views of Pikes Peak, stocked aid stations, and crew access for the 50k.