Colorado
Colorado Trail Running Calendar 2026-2027
Explore the best trail runs in Colorado for 2026-2027! Our updated list features 147 exciting trail runs across the region. Find your next trail run in Colorado below and join the trail community at these great events!
September 2026
A high alpine 50k in Nathrop, Colorado, featuring Colorado Trail singletrack, about 7,000 ft of climb and panoramic Sawatch Range views.
A fall trail event in Buena Vista, Colorado on September 27, 2026 offering a 14K trail race with over 500 feet of elevation gain and a 5K along the Arkansas River. Both races start and finish at Vendor Village near the Eddyline Beer Garden.
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.
October 2026
Trail races of 50K, 28K, and 15K at Hartman Rocks Recreation Area near Gunnison Colorado featuring varied terrain and broad mountain views.
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.
A point-to-point trail marathon and 30K in Colorado’s North Fork Valley at peak fall color, with mountain climbs to Inter-Ocean Pass and proceeds funding summer camp scholarships.
An inaugural Backyard ultrarun in Loma Colorado with repeated 4.17 mile loops until one runner remains, distance buckles and crew support.
Multiple race distances run near the Royal Gorge Bridge, including a 5K road run, an 8 mile trail race and a 13.1 mile half marathon, plus a free kids Dinosaur Dash and a virtual race option.
Experience the scenic single track trails of Steamboat Springs during the Emerald Mountain Trail Run. Choose between the 4 mile or 12k distances through aspen groves to support the local Boys and Girls Club.
Trail races on Philip S. Miller Park ridgelines include a family adventure run plus 5K, 10K, half marathon and 50K with chip timing and aid stations.
A scenic 5K through Estes Park during Elk Fest with shuttle transport from the Visitor Center and a finish at Performance Park.
OUTLAST Denver is a six hour trail challenge where runners complete a 5K every hour, earn patches or a medal for laps, and can place on a national leaderboard.
A Halloween themed community event in Aspen on October 4, 2026, with a timed 5.6K run and a 1 mile walk around Koch Park and Marolt open space. Leashed dogs are welcome and net proceeds benefit the Friends of the Aspen Animal Shelter.
A four-race trail series across city parks with increasing distances, chip timing, and cumulative awards for runners who complete all four events.
Multiple trail distances at Staunton State Park on October 10, 2026, from a steep 5K to a 50K ultramarathon, plus a 25K FishSlappers division that includes catching a trout; proceeds support conservation organizations.
A mountain backyard ultra in Estes Park with 4.167-mile loops every hour on trails beside Rocky Mountain National Park; last runner standing wins $1,000.