Trail Running calendar near Boulder 2026-2027

Lucky Lyons is a St. Patrick's Day themed run in Lyons, Colorado, featuring 5K and 10K races on mixed terrain. The 10K serves as a Bolder Boulder qualifier. Participants receive finisher dog tags, with awards for top age group finishers.

Race the Ranch is a snowshoe event at Snow Mountain Ranch YMCA in Colorado. Participants must carry snowshoes on courses featuring groomed trails and mountain terrain. Registration includes a YMCA day pass and finisher socks.

Run The Ranch offers trail races on the private, scenic grounds of Sylvan Dale Guest Ranch in Colorado. Choose from Friday evening 5k/10k races or Saturday's timed endurance runs and relay events. The event includes meal tickets, a mandator..

Celebrating its 11th year, the Mountain Ridge Trail Race winds through the rolling hills of Highlands Ranch, Colorado. Runners can choose from four distances, all on scenic dirt trails with rewarding front range views. The event is cupless,..

Explore Northern Colorado on the Poudre River Trail. This ultra offers 50 and 100-mile options, both for solo runners and relay teams. The unique 100-mile format combines a race day event with a virtual segment.

The Great Western Trail Race, a BOLDERBoulder qualifier in Severance, Colorado, is not scheduled for 2026 but may return. It has featured 5k, 10k, half marathon, and kids run distances. The event supports local community foundations and non..

Run the fast trails of Greenland Open Space in Colorado this May. Choose from four distances, from a 4-mile race to a 50K championship event. All runners receive a tech shirt and medal, with pizza waiting at the finish.

Niwot's Challenge is a secretive, map-and-compass adventure in Colorado for experienced navigators. It features unsupported loops with significant off-trail travel and elevation gain. Entry is by application only for a limited field of part..

Experience the 45th annual run along the scenic High Line Canal in Centennial. Enjoy chip timed 5K or 10K races followed by a pancake breakfast and beer garden.

Event Overview The Quad Rock 50 is a 50-mile trail race held in the hills west of Fort Collins, Colorado. The event takes place on a single-loop course through Lory State Park and Horsetooth Mountain Park. The course consists of two 25-mile..

Samson's Revenge is a trail race on the historic grounds of the YMCA of the Rockies in Estes Park. Runners can choose from 10k, 27k, or 55k distances on a challenging loop course. All participants receive a day pass to the YMCA and custom r..

The Farish Trail Race takes place on May 23, 2026 at the Farish Recreation Area in Woodland Park, Colorado. Participants can run a half marathon, 10K, 5K, or a free kids' one-mile event. The first 200 finishers get a special hat.

Event Overview The North Fork 50 Ultras is a trail running event held in Buffalo Creek, Colorado, southwest of Denver. The event offers two distances: 50 miles (with approximately 6,425 feet of elevation gain) 50K (31.1 miles, with approxi..

A 20K route around Turquoise Lake in Leadville, CO, running clockwise from Matchless Boat Ramp with paved and single track sections. Adult entry is $40 and under 18 run free. Parking is limited and a day use fee may apply.

Experience a scenic 5K trail run through subalpine forests and lakeside paths at the historic Leadville National Fish Hatchery. This cross country style event supports local youth athletics and recreation in the Leadville area.

Experience the beauty of the Rocky Mountains at the Summits Trail Runs. Choose from five distances ranging from six miles to a 14 hour challenge held on the scenic single track trails of Granby Ranch Resort.

Event Overview The Great Divide Ultra is a trail running festival held in early June in Divide, Colorado. The event takes place on the rolling meadows of Mueller State Park. The courses are 100% smooth single and double-track trail. Distanc..

Run the trails at Devil's Backbone Open Space in this classic 10k+ loop course. The event features old-school stick timing and finishes with an awards ceremony at a local brewery. This race series will conclude after the 2028 edition.

The Barr Lake Trail Race offers a flat, fast course on dirt trails around the scenic lake. With distances from 5K to 50K, runners can enjoy views of the Colorado Front Range. The event is in its seventh year and features a cupless initiativ..

Leadville Trail 100 Run Camp The Leadville Trail 100 Run Camp takes place over three days from June 19-21, 2026. It is an introduction to the Leadville Trail 100 Run course. The camp features guided group training runs, both day and night,..