Trail Running Calendar Colorado 2026-2027

Grand Valley Backyard Ultra is a last-person-standing trail event near Fruita, Colorado where runners complete repeated 4.167 mile loops with one hour to finish each loop until only one runner completes an extra lap.

Multiple race distances run near the Royal Gorge Bridge, including a 5K road run, an 8 mile trail race and a 13.1 mile half marathon, plus a free kids Dinosaur Dash and a virtual race option.

Experience the scenic single track trails of Steamboat Springs during the Emerald Mountain Trail Run. Choose between the 4 mile or 12k distances through aspen groves to support the local Boys and Girls Club.

Multiple trail races and a family obstacle run take place on Castle Rock ridgeline trails, with timed 5K to 50K options, chip timing, finisher medals and proceeds from the liveBIG race supporting the town’s Therapeutic Recreation Program.

The Camp 4 Coffee Cart to Cart Trail Race will take place in Crested Butte on Saturday 3 October 2026. You can run between 10 and 19 miles.

A six-hour trail challenge in Littleton where runners complete a 5K each hour for six hours, totaling 18 miles if completed. Trail terrain, hourly elimination, tiered patches and medals, and national leaderboard prizes highlight the format.

A Halloween-themed Aspen event with a timed 3.5 mile trail run and a 1 mile walk, pet-friendly course through Marolt foot path and Moore open space, water stations, costume prizes, raffle prizes, food trucks, and proceeds to the Aspen Anima..

A four-race trail series in city and county parks with increasing distances and varied terrain. The races are chip timed and overall awards require completion of all four events.

Multiple trail distances at Staunton State Park on October 10, 2026, from a steep 5K to a 50K ultramarathon, plus a 25K FishSlappers division that includes catching a trout; proceeds support conservation organizations.

A loop endurance event near Castle Rock, Colorado honoring two women with long lives. Choose **104 miles** or **52 miles** on a 3.25-mile loop, with solo and relay options plus camping, food trucks, and live music.

Indian Creek Trail Runs in Sedalia, Colorado on October 17, 2026 offers multiple trail and ultra distances through montane forests, aspen groves, red rock formations and prairie vistas with city views from several viewpoints.

Multiple trail distances run through Palmer Park in Colorado Springs with city and Pikes Peak views. Courses are marked, longer distances have aid stations, reusable cups are required and finish line drop bags are available.

Trail marathon and half near Fort Collins along redstone singletrack and technical rock sections, with stocked aid stations, drop bag options, and caps of 400 entries per distance.

Trail races at Bear Creek Lake Park offering 5 miles or a two-lap 10 miles on single-track dirt. Registration includes park admission, a finisher meal and refreshments; 10 mile finishers receive a commemorative mug.

A four-race trail series in city and county parks with increasing distances and varied terrain. The races are chip timed and overall awards require completion of all four events.

Methodist Mountain Ultra The Methodist Mountain Ultra (MMU) is a trail race set on the Methodist Mountain trail system near Salida, Colorado. It takes place at the northern end of the Sangre de Cristo mountains. The event features two dista..

A single-loop trail event in Cañon City that follows the Arkansas River, Tunnel Drive, Royal Gorge singletrack and Temple Canyon, reaching a 7,109 ft high point. Distances offered include 35 mile/50k, 35k and 10k.

Trail races at Bear Creek Lake Park in Lakewood, CO on Sun, Oct 25, 2026 offering 5 km, 15 km, a 5+15 Double, and a Kids 1 km. Mostly dirt single and double track with short steep hills and clearly marked routes.

MonsterDASH Louisville on Oct 25, 2026 offers a new half marathon plus 5k, 10k and a kids mile with costume contests, expo, and themed runner perks.

A four-race trail series in city and county parks with increasing distances and varied terrain. The races are chip timed and overall awards require completion of all four events.