Trail Running calendar near Castle Rock 2026-2027

Six trail races across Summit County, Colorado, in summer 2026. Series registration includes long and short course options with adult, youth, and non binary categories and events at multiple Summit County trail heads.

Trail races at Granby Ranch Resort in Colorado offer multiple distances including a 14 hour Elevation Challenge based on completed loops. The combined field is capped at 250 and the event includes aid stations, drop bag options, and on-site..

A weekend trail running festival at Mueller State Park in Divide, Colorado featuring distances from 25K to 100 miles on smooth single and double track. The program includes a Saturday evening Dark Divide Night Run and shuttle parking for so..

Aiden's Adventure 5k is a community run/walk honoring a young child's memory. The event features a flat dirt trail 5k, a kids' dash, and family-friendly activities like carnival games and a butterfly release. All proceeds support local char..

Haul Ass Ultra at Luvin Arms in Erie, CO features multiple distance and timed events on a mostly flat off road loop with Rocky Mountain views and running past sanctuary animals; a portion of proceeds supports the sanctuary.

A looped 10k plus trail run at Devils Backbone Open Space in Loveland featuring marked singletrack, an aid station near mile three served twice, old school timing with a finish stick, and an awards gathering at Loveland Aleworks.

Looped trail races at Barr Lake State Park in Brighton Colorado offer 50K, 30K, half marathon, 15K and 5K options on dirt surfaces with lake and Front Range views. Aid station coverage varies by distance.

Races through Garden of the Gods Park include a 10 mile road, 10K road and 10K trail, all finishing at Rock Ledge Ranch. The routes pass towering sandstone formations, include aid stations, and end with on-site post-race food and music.

Prepare for the Race Across the Sky at this three day training camp in Leadville. Run key sections of the 100 mile course alongside veteran guides and attend educational panels on nutrition and biomechanics.

A trail race at Garden of the Gods on June 20, 2026, offering 100K, 50K, and 35K courses that feature significant climbing, multiple aid stations, and a start/finish at Rock Ledge Ranch in Colorado Springs.

Experience up to three miles of messy fun at the Colorado National Speedway. Navigate obstacles by crawling wading and sliding through the mud with friends and family during this unique event in Dacono.

Test your strength at this exclusive obstacle course event in Peyton featuring a three lap 3K race and a one mile kids run. Navigate rigs, rope climbs, and heavy carries in a small field of only fifty athletes.

Summer Vibes Bike Rally & Run Festival in Lyons Colorado pairs gravel and road bike rallies with trail running, relays, live music, recovery pools and camping for a combined endurance and festival weekend.

A multi-event Colorado series of four half marathons and a 25K across summer 2026, organized by HAL Sports with races run by local nonprofits. Participants may register for three, four, or all five events.

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.

Experience a high altitude outdoor festival in the highest incorporated town in North America featuring trail running mountain biking and duathlon. Enjoy a weekend of racing and meadow camping surrounded by 14,000 foot peaks.

On June 27, 2026 in Leadville, Colorado two trail races run to Mosquito Pass at 13,185 feet. The marathon is 26.4 miles and the Heavy Half is 15.46 miles, with multiple on-course aid stations and a Leadville Trail 100 qualifying allocation.

An overnight endurance event in Highlands Ranch, Colorado offering solo and team relay options on a 10.3 miles dirt loop beneath a full moon. Two aid stations, drop bags, medical support and a headlamp requirement are provided.

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.

Experience a half marathon in the mountains of Nederland Colorado. This event features a significant elevation gain of 4226 feet with the summit always in view.