Trail Running calendar near Boulder 2025-2026

Join the USCSA Cross Country Ski Racing Festival at Snow Mountain Ranch in Granby Colorado on Jan 24 and 25 2026. Collegiate teams and middle and high school racers take on classic distances and a skate sprint over two action packed days.

Brave the cold at the Freakin Freezin 5K in Denver on Jan 25 at Northfield High School. Run a flat, car free trail 5K or go virtual, earn a custom finisher medal, and get guaranteed swag if you register by Jan 15.

The Sourdough Snowshoe Race in Nederland, CO is a donation based backcountry event offering 18K and 30K routes where snowshoes are required. Enjoy rugged alpine scenery with a warming tent and hot drinks at the finish.

Join the Super Sunday 5K on February 8, 2026 in Littleton for a scenic run along the Mary Carter Greenway. Celebrate at a post race party at Breckenridge Brewery Farmhouse with 20% off food and drinks and community fun.

Race The Ranch is a scenic snowshoe race at Snow Mountain Ranch in Granby Colorado on April 4 2026, with 50k, 25k and 5k loop options over snowy singletrack and groomed trails. Finishers receive a custom bib, Fractel beanie and engraved Mii..

Join Run the Ranch April 10 and 11, 2026 at Sylvan Dale Guest Ranch in Loveland, Colorado for trail races on private ranch trails, from 5K and 10K to timed 4 hour, 6 hour and 12 hour solo and relay events. Virtual options available.

Run scenic single track trails around Highlands Ranch with options from 5K to 21 mile courses. Enjoy rolling climbs, aid stations, and a cupless race with reusable cups available for purchase at registration.

Take on the scenic Poudre River Trail April 11 and 12 2026 in Northern Colorado with 50 and 100 mile solo and relay options. Stocked aid stations, finisher swag, belt buckles for solos and a lively post race party await.

May 2, 2026: Greenland Trail Races at Greenland Open Space in Larkspur offer distances from 4 miles to 50K plus a virtual option. Scenic dirt trails with Pikes Peak views, aid stations, tech shirts, medals, and a 50K buckle.

Niwot's Challenge is a by invitation only endurance event near Sedalia, Colorado that prizes off trail navigation and self reliance over racing. Limited to 40 entrants, it offers routes up to 100 miles for experienced wilderness runners.

Take on Quad Rock 25 or 50 mile trail races through Lory State Park and Horsetooth Mountain Park near Fort Collins. Rugged singletrack, big climbs and full aid stations make this scenic loop a true mountain challenge.

Run the North Fork 50 Mile or 50K on scenic singletrack around Buffalo Creek, Colorado. Choose your distance, enjoy aid stations and a festive finish, and support the North Fork Volunteer Fire Department.

Run the Summits Trail Runs on June 6, 2026 at Granby Ranch Resort, Colorado, with options from a 6 mile to a challenging 50k. Experience single track trails, alpine meadows, and big climbs in a limited field for an intimate mountain race.

Explore high alpine loops at Mueller State Park on June 6 and 7 for the Great Divide Ultra, with distances from 25k to 100 mile and night run options for 25k and 50k. Scenic views, supportive aid, and standout finish swag await.

Run the Crazy Legs 10k+ at Devil's Backbone Open Space in Loveland, Colorado, a scenic looped course through Hidden Valley and Hunter Loop. Expect volunteer staffed aid, local sponsors, and a friendly community vibe; park pass required.

Run scenic dirt trails around Barr Lake State Park on June 13, 2026, with distances from 5K to 50K to suit every trail runner. Enjoy open Front Range views, gentle elevation and aid stations on the longer courses.

Join the Leadville Trail 100 Run Camp in Leadville, Colorado, June 19 to 21 for a three day preview of the LT100 course. Enjoy guided day and night runs, gear demos, shuttles and recovery services for a full race ready experience.

Race in the Clouds Alma Dirt Festival runs June 25 to 28, 2026 in Alma, Colorado at 10,600 ft. Mountain biking, trail runs, an off road duathlon, youth races and meadow camping offer high country climbs and single track thrills.

Hit the foothill dirt trails at Lory State Park on June 27 for the Timberview Trail Run with 10 mile, 5 mile and beginner friendly 5K options. Finish with pancakes, craft beer and finisher swag at this USATF sanctioned community favorite.

Run the Life Time Leadville Trail Marathon or Heavy Half on June 27, 2026, tackling high alpine singletrack and dirt roads through historic mining country up to Mosquito Pass at 13,185 feet. Expect a challenging, possibly snowy race with fu..