Trail Running Calendar Colorado 2026-2027

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 0.8 mile foot race from Telluride to San Sophia ridge via the Telluride Trail, the Rundola raises funds for the Good Neighbor Fund and awards medals and prizes across age and gender categories.

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.

A high altitude 50 mile out and back near Leadville with about 7,500 feet of climbing, aid stations, designated crew zones, shuttle parking, and LT100 qualifier coins available.

Experience the STRS Horseshoe Gulch Grind in Breckenridge with short and long course options. This trail event offers categories for adults and youth starting from the Blair Witch Trailhead.

A 100-mile trail race in Ouray, Colorado, with about 41,862 feet of elevation gain across fourteen climbs and a 52-hour cutoff. Runners must complete eight hours of volunteer service or pay a $100 opt-out fee; winners face drug testing and..

Experience a high altitude mountain race through the Sawatch range of the Colorado Rockies. This 101 mile loop features historical ghost towns and alpine passes with over 23000 feet of elevation gain.

A two day festival in Centennial Park, Cañon City on July 17–18, 2026 featuring whitewater competitions and land based events. The program includes running and mountain bike races, raft rodeo, SUP activities, cardboard boat races and a ween..