Trail Running Calendar Colorado 2026-2027

At 10,600 feet in Alma, Colorado, Race in the Clouds is a June 25 to 28 Dirt Fest featuring mountain biking, trail running, off road duathlon, youth races and meadow camping, with USA Triathlon sanctioning and age group awards.

A rugged, mostly off-trail 50k around Silverton, CO, with about 19,000 ft of ascent and a roughly 19-hour cutoff. Entry is limited and restricted to club members with proven mountain navigation experience.

Trail races at Lory State Park on June 27, 2026 featuring 10 mile, 5 mile and 5K courses with treetop views of Horsetooth Reservoir and aid stations using biodegradable cups and dog water bowls.

A high altitude trail marathon and 15.46 mile Heavy Half through Leadville’s historic mining district, topping out at 13,185 feet on Mosquito Pass. General registration is sold out and a waitlist is available.

Chase the Moon is an overnight fixed time trail event in Highlands Ranch, Colorado with solo 12, 6 and 3 hour races, a 50K and three and five person relays. Runners complete marked loops on dirt trails with aid stations and drop bag support..

A backyard ultra on the paved Lake Estes trail where runners complete 4.252 mile loops each hour until one runner finishes a loop alone. The event records yards for DNFs and offers on-site aid and athlete village space.

SBT TRL in Steamboat Springs offers trail races at Howelsen Hill as part of the SBT GRVL weekend. Participants can choose a 5 km or 10 km distance with registration open from February 10 to June 27, 2026.

Operation HAYSTACK is a half marathon in Nederland, Colorado on June 27, 2026. The course covers 13.1 miles with 4,226 ft of elevation gain and the listed entry price is $105 plus tax.

A three-race trail series at Sunlight Mountain Resort near Glenwood Springs featuring a 5K, 10K and half marathon, with specified bib pick up, aid station info, entry fees, age categories and podium prizes.

Alderfer 5K Trail Race at Alderfer Ranch in Evergreen Colorado is a 5 km trail event with shuttle service from Wulf Rec Center. The course is cup free with no aid stations, and water and refreshments are available at the venue.

Trail Town Ten in Ridgway features a 10 mile lollipop course with San Juan Mountain views and a 5 mile out-and-back on the same dirt roads. The event is coordinated with Ridgway RiverFest and benefits the Uncompahgre Watershed Partnership.

A professional pack burro race in Cripple Creek on June 28, 2026, held within the Donkey Derby Days festival. The 6 mile course features chip timing, staffed checkpoints, cash prizes, and family activities at the start and finish.

A 5K run/walk in Winter Park, Colorado following the Fraser River Trail from Gondola Plaza to the Rendezvous Event Center, with an after party featuring refreshments, awards and prize giveaways.

A Fourth of July 5K in downtown Leadville, CO, held above 10,000 feet. Proceeds support local youth athletics and youth entries are free.

An uphill foot race in Telluride that benefits the Good Neighbor Fund, following the Telluride Trail to San Sophia ridge. The event uses age and gender categories, awards medals by category, and lists specific bib pickup dates before the ra..

Experience a mountain run to the summit of an 10,839 foot former volcano. This 8 mile out and back course features 2200 feet of climbing and panoramic views from a historic fire lookout tower.

A historic uphill trail race in Vail, Colorado celebrating its 50th edition on July 5, 2026. The 12.2K (7.6 mile) route gains 2,128 feet and finishes at Mid-Vail with aid stations, awards, a raffle and post-race refreshments.

Experience high altitude trail running through historic Colorado ghost towns and mines at over 10000 feet. Choose from distances ranging from 10 miles to 100 miles in the scenic South Park Valley.

A 100-mile loop in the San Juan Mountains near Silverton Colorado featuring about 66,500 feet of total elevation change and alpine terrain. The event publishes runner and volunteer manuals and supports local organizations.

A historic Crested Butte trail event offering 15 km and 25 km runs plus a technical 25 km mountain bike course. Routes include long climbs, rocky singletrack and a Green Lake checkpoint with limited aid.