Trail Running calendar near Longmont 2026-2027

A family-friendly *5K* mud run at Colorado National Speedway on June 20, 2026, with obstacles, waist-deep mud pits, slides, a pre-party and an after-party with music and food. Registration tiers include standard and VIP options.

A one day festival in Lyons Colorado combining gravel and road bike events, trail running races, live music, pool areas and camping. Distances include 100K and 50K gravel rides plus a 5 mile run and several relays.

A five-race Colorado series consisting of four half marathons and a 25K across mountain towns and trails, held June–September 2026, with series scoring and events organized by HAL Sports and local nonprofit race organizers.

A community-focused trail festival in Gold Hill, Colorado, with 28K, 12K, 5K and Kids 1K races, a shuttle from Boulder, and proceeds supporting wildfire preparedness for the town.

A USATF sanctioned trail event at Lory State Park on June 27, 2026 offering 5K, 5 mile and 10 mile routes with scenic foothill views, aid stations with biodegradable cups, dog water bowls, bib pickup the day before and post race food.

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.

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.

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.

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 12.2K uphill trail race in Vail, Colorado marking its 50th running, the Vail HillClimb gains 2,128 feet across dirt and gravel service roads to finish at Mid-Vail, with aid stations, race shirts, awards by age group and a post-race raffle..

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.

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.

High-altitude trail races on Vail Mountain offering 10K and 5K courses that start near Gondola One, feature singletrack and gravel sections, on-course aid stations, post-race refreshments, and age-group awards.

Repeating 2 km out and back laps on the Thumb Open Space trail in Estes Park. Participants collect a poker chip at each turnaround and the most chips wins during a sunup to sundown timeframe; 35 spots and a $100 entry fee.

A community trail event at JCC Ranch Camp on Saturday July 18 offering 5k and 10k trail options, sliding scale entry, on course water and clinic support, plus post-race tie dye and craft activities for finishers.

Alpine ultramarathons in State Forest State Park between the Never Summer and Medicine Bow ranges. Options include 100 km, 60 km or both, with high elevation terrain, staffed aid stations and limited cell service.

Held July 25, 2026 in Conifer, Colorado, the Elevation Run/Walk offers a 10K, a USATF certified 5K and a 2 mile fun run while raising funds for local school boosters and leading into the Elevation Celebration festival with music and vendors..

A single 200-mile loop around Summit County, Colorado on trails, 4WD roads and rec paths, with elevations above 9,000 ft and sections over 12,700 ft. The field is capped at 75 runners and includes 12 aid stations, four sleep stations, and l..

STRS #4 - Tom's Baby on July 29, 2026 takes place at Tom's Baby Trailhead in Breckenridge, CO, offering short and long course entries with adult, youth, and non-binary categories and published entry fees.