Trail Running calendar near Boulder 2025-2026

Join the Life Time Silver Rush 50 Run in Leadville for a high alpine 50 mile out and back plus 15 mile and 5K juniors. With seven aid stations and Leadville Trail 100 Run qualifier spots, this is a true mountain challenge.

Experience high alpine trails and rugged scenery in the Never Summer 100k and 60k from Gould, Colorado, with challenging climbs across ridges, peaks and alpine lakes. Choose 100k, 60k or the Dirty Double for a true mountain ultra adventure.

The Summit 200 is a 200 mile loop around Summit County Colorado that climbs into high alpine single track above 12,700 feet. Capped at 100 runners and requiring a prior 100 mile finish, it is a remote, high altitude test of endurance.

Join the Wild West Relay, a scenic point to point 200 miles across Colorado from Fort Collins to Steamboat Springs. Run solo or with teams from 1 up to 12 people as you tackle mountain passes, open roads and big western views.

Experience high alpine trails above 10,600 feet at the Sheep Mountain Trail Runs in Fairplay Colorado on August 1, 2026. Choose from half marathon, 50k or 50 mile distances for a rugged, scenic challenge.

Run the Lory Summer Trail Series in August at Lory State Park: four midweek trail races from 5K to 12K with scenic climbs and friendly competition. Stay after each race for pizza, drinks and a free vintage shirt, plus series awards.

Run the Lory Summer Trail Series in August at Lory State Park: four midweek trail races from 5K to 12K with scenic climbs and friendly competition. Stay after each race for pizza, drinks and a free vintage shirt, plus series awards.

Run the Rockies Trail in Frisco, CO features 5K to half marathon routes on the scenic Frisco Peninsula with lakeshore finishes and reservoir views. Finishers receive a gift and an afterparty with food, music and beer for 21+.

Take on the iconic Leadville Trail 100 Run, a 100 mile ultramarathon through the Colorado Rockies that climbs to Hope Pass and delivers breathtaking high altitude views. A true test of endurance and grit.

Run mountain trails in Fraser, Colorado on August 22, 2026 with a scenic high elevation half marathon or a friendly 5K along dirt roads. All proceeds benefit the Shining Stars Foundation and dogs on leash are welcome.

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..

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

Challenge yourself on scenic Ridgeline Trail at Rock Hawk Trail Races on August 29, 2026 in Philip S. Miller Park, Castle Rock, CO. Choose from 5K to 50K distances, enjoy rolling terrain and finisher awards while supporting local trails.

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.

Ned Ned Run in Nederland Colorado blends scenic trail and road running through the foothills, offering a half marathon, 10K and fun 5K for all abilities. Family friendly and costumes encouraged, with leashed dogs welcome in the 5K.

Join the Snow Mountain Ranch Trail Running Festival in Granby, CO for scenic high country trails and big mountain views. Choose 50K, 33K, half marathon, 10K or 5K and enjoy on site camping and bib pickup race day.

Take on the Black Squirrel Half Marathon at Lory State Park near Bellvue, Colorado, a 13.5 mile trail challenge with about 2,000 feet of climbing across scenic singletrack. Limited to 400 runners, the day also offers a free 1 mile kids race..

Red Feather Trail Jamboree in Red Feather Lakes Colorado offers a weekend of scenic singletrack racing, camping and a community dinner at Ben Delatour Scout Ranch. Choose 50 Mile, 50K or Half Marathon, capped at 500 runners.

Test your limits at 24 Hours of Palmer Lake, a low key community driven endurance run atop the Palmer Divide at 7,240 feet. Short loop laps keep the vibe close and the first ten to reach 100 miles earn an on site buckle.

The Bear Chase is a two day trail running festival at Bear Creek Lake Park on October 3 and 4, 2026. From ultras to fun 5K and 10K options, enjoy scenic single track loops with aid stations and live split tracking.