Trail Running Calendar Colorado 2026-2027

A mountain trail race in Vail on August 1, 2026 featuring an uphill 6.9 km course with about 2,013 feet of gain, singletrack and doubletrack terrain, an aid station, post race refreshments, awards and a raffle.

Two Brothers Up and Down in Idaho Springs offers two uphill out and back races on mixed dirt and paved roads, with steep sections and an aid station on the 10k. Both races start and finish at Courtney Riley Cooper Park.

A pack burro race in Buena Vista Colorado on Aug 2 2026 with 13.1 mile and 7.3 mile courses offered both with and without burros. Burro teams must meet specific equipment and conduct rules and finishers receive a gift and a meal.

A four-race August trail series at Lory State Park in Fort Collins featuring 5k, 10k and 12k courses with chip timing, series points and end-of-series awards. Post-race pizza and beverages are provided.

High Five 100 is a self guided 100 mile challenge from Lake City, Colorado that visits 24 proof points and checkpoints in order. Runners navigate their own route, face significant elevation gain, and must return within a 48 hour cutoff.

A two day running event in Snowmass Village on August 7 and 8, 2026 offering 3.76k, 5k and a single 10k plus an 18.76k challenge. Finishers receive a free New Belgium brew and event medals; proceeds support local nonprofits.

Trail races of 5k, 10k and half marathon on Frisco Peninsula trails with lake and mountain views, single-track sections, chip timing, aid stations, and post-race food and beer for participants 21 and older.

Two day mountain bike and trail running event in Steamboat Springs on August 8 and 9 2026. Multiple distances from a 52 mile solo bike to 26.2 and 13.1 mile runs, with proceeds supporting local youth and trail organizations.

Trail run at Rampart Reservoir with 8 mile and 16 mile options on single track and rocky sections. Entry is limited to 150 and registration closes August 5, 2026.

A traditional pack burro race at 10,200 ft in Leadville, Colorado on August 9, 2026. Teams of a runner and a burro follow marked mountain routes over historic mining trails with long and shorter course options and strict animal welfare rule..

Experience a focused trail run through the hills of Lory State Park with 1,700 feet of elevation gain. Enjoy a post-race social with pizza and beer in a scenic outdoor setting limited to 100 participants.

A four‑race midweek trail series at Lory State Park in August 2026 offering 5k, 10k and 12k courses with varied elevation. Series and per-race registration, post-race food and drinks, and end-of-series awards for top points scorers.

STRS #5 Carter Park Scurry in Breckenridge on August 12 2026 offers short and long course entries across adult youth and non-binary divisions with published entry fees and a course map.

A high-mountain 100 mile ultramarathon north of Durango, Colorado, with about 19,000 ft of climbing and a 38 hour cutoff. The 2026 race is sold out; satellite tracking and specific mandatory gear are required.

A mostly dirt and trail race along Boulder Reservoir in Boulder, Colorado, with about 200 feet of elevation gain. Distances range from a 10K to a full marathon, plus a relay option.

Trail ultras from Roxborough State Park to Sharptail Trailhead featuring sustained climbs, technical singletrack, and a long runnable finish, with full aid support and an emphasis on land stewardship.

Experience the trails of Cheyenne Mountain State Park with three race distances ranging from a 5K walk to a 25K mountain challenge. This chip timed fundraiser supports park conservation through scenic and high elevation courses.

A multi-distance trail event at Standley Lake in Westminster, Colorado featuring 50K, 35K, half marathon, 10K and 5K on packed dirt trails with aid stations, drop bag access, parking at Wayne Carle Middle School and lakeside views of the Fr..

Summit Grays and Torreys Peaks in this 8.8 mile Colorado endurance event. Participants must carry a 20lb dry load while tackling 4,101 feet of elevation gain.

A community backyard ultra at Loudy Simpson Park where runners repeat a 4.167 mile loop each hour until one remains. A separate Citizens Race covers a single 4.167 mile loop along the Yampa River.