Trail Running Calendar Colorado 2025-2026

Welcome to Colorado's premier trail running calendar for 2025-2026! Recognized as a trail runner's haven, Colorado seamlessly blends bustling urban settings with pristine mountain terrains. Whether you're a native, a newbie, or a visitor exploring the Centennial State's running trails, our calendar ensures you don't miss out on any event.

Denver, the renowned Mile High City, beckons runners with its urban-meets-nature charm. Iconic routes like the Cherry Creek Trail zigzag right through the city's pulse. Venturing south, Colorado Springs, dubbed the "Olympic City", boasts of trails skirting the monumental Garden of the Gods. Here, a run transcends the ordinary, offering an experience akin to striking gold.

For those seeking a quiet escape, Aurora presents peaceful reservoir paths, making urban detox achievable. If the allure of academic vibes mixed with nature captivates you, Fort Collins and its famous Horsetooth Reservoir trails won't disappoint. Meanwhile, Lakewood introduces runners to nature's canvas with the Red Rocks painting every run. And let's not forget Boulder, offering a diverse range of trails set against the stunning backdrop of the Flatirons.

Join the Wild West Relay, a scenic point to point run of roughly 200 miles from Fort Collins to Steamboat Springs. Solo runners and teams of all sizes are welcome for an unforgettable overnight relay adventure.

August 2026

Take on the Sheep Mountain Trail Runs in Fairplay Colorado on August 1 2026 with 50 mile, 50k and half marathon options across high alpine trails. Expect rugged terrain, big mountain views, well stocked aid stations and a finisher award.

Take on the Kennebec Mountain Run, a 15 mile trail with about 3,100 feet of climbing to a high alpine pass. Limited to 150 runners, the grassroots race raises funds for La Plata County Search and Rescue and showcases Colorado scenery.

Take on the Aspen Backcountry on August 1 in Rio Grande Park with three distances from a 50K to a hearty half marathon over rugged alpine trails and big elevation gain. Celebrate at the finish festival with live music, food trucks and famil..

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.

High Five 100 in Lake City Colorado on August 7 2026 is a rugged mountain ultra of about 100 miles and 40,000 ft of climbing with five 14er summits. The unmarked, self supported route uses checkpoints for aid and has a 48 hour cutoff.

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+.

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 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.

Challenge high elevation trails above historic Telluride with 13, 24 or 40 mile courses across alpine tundra, exposed ridgelines and mountain passes. Big climbs, epic views and true mountain running in the San Juan Mountains.

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 high country trails above Steamboat Springs at the Continental Divide Trail Run on August 29, 2026. Choose 50K, 16 Miler, or 5 Miler for stunning Yampa Valley vistas and challenging alpine climbs.

September 2026

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.

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.