Trail Running calendar near Boulder 2026-2027

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, organized by the Leadville Sports Hall, with youth entry free and proceeds supporting local youth athletics.

A historic mountain trail race in Vail, Colorado covering 12.2K with 2,128 feet of ascent. The 50th Vail HillClimb awards finisher medals, age group prizes, and provides aid stations, race shirts and postrace refreshments.

Community outdoor event in Golden offering a 12 mile bike ride, a 5 mile hike, and a 10 mile run at South Table Mountain. Participants must sign a Latinos Outdoors waiver and bring appropriate gear.

A high altitude trail running event in Como and Grant, Colorado offering ultras and shorter trail distances across alpine meadows, single track and historic mining terrain, with aid stations, drop bag options, crew and pacer rules.

A series of Leadville trail races on July 11, 2026, highlighted by a 50-mile out-and-back with 8,000 feet of gain, organized aid stations, and a spot as a qualifier for the Leadville Trail 100 Run; 15-mile and juniors 5K distances are also..

The STRS Horseshoe Gulch Grind will take place in Breckenridge on Wednesday 15 July 2026.

A mountain trail event on July 18, 2026 featuring 10K and 5K courses on Vail Mountain. Courses were rerouted for 2026 and include aid stations, high-altitude terrain, age-group awards, and post-race refreshments.

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..

Experience a historic Colorado tradition where runners and burros compete together. Navigate mountain trails and high altitude passes while carrying traditional mining gear in this unique world championship event.

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.

An overnight team relay covering 200 miles and 36 legs from Fort Collins to Steamboat Springs, crossing two mountain passes. Multiple team categories are offered and teams choose between supplying volunteers or donating to Windsor Gives.

Sheep Mountain Trail Runs in Fairplay, CO offers 50 mile, 50k and half marathon courses at high elevation with technical trails and forest roads. The event includes stocked aid stations, a finisher medal, drop down options and a 16 hour tim..

A mountain trail event in Winter Park, CO offering 50K, 21K, and 10K courses across high alpine singletrack with significant elevation gain, staffed aid stations, age group awards, and town finish at Rendezvous Event Center.

A mountain trail race from Vail Village to Mid-Vail covering about 6.9 km with roughly 2,013 feet of ascent, staffed aid stations and finish refreshments. Age-group awards and race t-shirts are provided.

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.