Boulder Rez Marathon

Run scenic single track trails near the Denver skyline at the Great Trailhead Foot Race in Bear Creek Lake Park on October 18, 2025. Choose 5 or 10 miles, get a tech tee and post run party, and 10 mile finishers earn a mug.

Join the Expo Park XC Runs in Aurora on Sunday October 19 for youth and adult cross country races from 1k to 5k. Enjoy mostly grassy, gently rolling courses with a creek crossing and bale jumps for a fun, family friendly race day.

Tackle scenic dirt trails at Bear Creek Lake Park with 5 km, 15 km, a 5 plus 15 double, or a kids 1 km. Registration includes socks or a neck gaiter and a pancake breakfast while kids earn a stuffed bear at the finish.

The Colleen De Reuck XC Classic is a cross country running event held annually at Harlow Platts Community Park in Boulder, Colorado. Honoring renowned distance runner Colleen De Reuck, the race promotes health, fitness, and celebrates local..

Run the Louisville Trail Race on November 15, 2025, amid the Flat Irons with 13.1, 10K or 5K dirt courses on scenic trails. Enjoy post race festivities and bring a reusable cup or purchase one onsite.

Take on the Thumbs Up Vertical Challenge in Estes Park CO on December 6, 2025, a small field test of grit with steep single track laps and sweeping views of Longs Peak and Mount Meeker. With only 30 spots, this intimate winter climb rewards..