Trail Running Calendar Colorado 2026-2027

Emerald Mountain Epic in Steamboat Springs on August 8 and 9, 2026 is a two day mountain bike and trail running weekend on scenic singletrack dirt trails. Race marathon, half or bike distances with a limited field of 500 per day.

Take on the San Juan Softie 100, a 100 mile mountain ultra out of Durango, Colorado, that winds through San Juan peaks at nearly 10,000 ft with over 20,000 ft of vertical gain. Runners have a 38 hour cutoff.

Run along Boulder Reservoir on flat, mostly dirt trail courses with sweeping Rocky Mountain views. Choose from 10K, 3 4 marathon, half, full marathon or relay, with USATF certified courses, a shirt and a finisher medal.

Roxborough Ultras features 50K and 50M all trail ultramarathons in Roxborough State Park with sustained climbing, technical terrain, and big elevation gain. August is hot and dry with limited shade and spaced aid stations, so carry water an..

Run the scenic Leadville Trail 10K on August 16, 2026 in historic Leadville, Colorado, tracing the opening miles of the LT100 course at over 9,700 feet. Enjoy a fast out and back on paved and dirt roads with aid at the turnaround and awards..

Join the Into the Hills Eltuck 5k, part of a four race midweek trail series at Lory State Park in Bellvue. Chip timing, series points and vintage Gnar shirts add fun, while varied valley and hill courses challenge every runner.

Tackle a rugged 10k through Lory State Park with roughly 1,700 feet of climbing and chip timed results in this midweek trail series. Grab a vintage Gnar shirt and enjoy pizza and drinks after the run.

Tackle the legendary Leadville Trail 100, a 100 mile out and back ultramarathon through the high Colorado Rockies with steep climbs, technical singletrack and alpine passes up to 12,500 feet. Expect epic views, serious altitude and belt buc..

Run the Byers Peak Stampede in Fraser Colorado for a scenic half marathon or 5K on high country dirt roads with Rocky Mountain views. Family and dog friendly event with proceeds benefiting families affected by cancer.

Staunton Rocks! Marathon and Half deliver high altitude singletrack through Staunton State Park, offering sweeping mountain views, alpine wildlife, and serious vertical gain. With just 150 spots per distance, this rugged trail run fills fas..

Run high in the San Juan Mountains above historic Telluride on rugged trails across old mining roads, exposed ridgelines and alpine tundra above 13,000 ft. Distances from a 5 km hill climb to a new 100 km offer epic options for every trail..

The Lory Summer Trail Series will take place in Bellvue on Tuesday 25 August 2026. You can run 12 kilometers.

Run Rock Hawk Trail Races at Philip S. Miller Park in Castle Rock with 5K, 10K, 25K and 50K on rolling singletrack and scenic ridge views. Proceeds support open space and the race offers chip timing and live split tracking.

Run high alpine trails around Steamboat Springs on August 29, 2026 with choices of 50K, 16 mile and 5 mile courses, featuring big climbs and stunning mountain views. Proceeds support the Trail Maintenance Endowment Fund and the race is cupl..

Run 40 miles across the Elk Mountains from Crested Butte to Aspen along the Grand Traverse route with more than 6,000 feet of climbing. A fundraising point to point ultramarathon with aid stations and a post race shuttle.

Run the Cirque Series at Arapahoe Basin: a scenic 9.4 miles with 2,211 ft of climbing on high alpine trails around Montezuma and Little Lenawee. Finish in Mountain Goat Plaza with live music, food, and festival vibes.

Join the American Heroes Run in Longmont, Colorado on September 11 and 12 to honor the victims and first responders of 2001 on a flat, fast 1.05 mile loop. Choose distances from 5K to 100 mile with timed and virtual options plus shirts and..

Join the Ned Ned Run in Old Town Nederland, Colorado in September, a 44 year tradition offering road and trail distances from a scenic 5K to a tough half marathon. Family friendly and costumes encouraged; dogs on leash welcome in the 5K.

Run high alpine trails at Snow Mountain Ranch in Granby Colorado on September 12 2026. Choices from 5K to 50K plus Moosehead challenges, scenic dirt and grass routes with on site lodging and camping.

Take on the Black Squirrel Half Marathon in Lory State Park, a scenic 13.5 mile trail challenge with about 2000 feet of climbing across high country singletrack. Limited to 400 runners, it delivers tough climbs and sweeping mountain views.