Trail Running calendar near Aurora 2026-2027

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.

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 four-race trail series across local parks with increasing distances, chip timing, and series awards for runners who complete all four events. Entrants must be 15 or older and registration is online only.

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.

Run the Rocks is a fundraising event at Red Rocks Park and Amphitheatre in Morrison, Colorado on October 11, 2026. It offers a 5k and a 1.3 mile family course and raises funds for lung disease education, advocacy and research.

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.

Urban trail races at Palmer Park in Colorado Springs offering 50K, 25K, 10K and 5K on marked single track with aid stations, drop bags, and no pacers. Organized by Aravaipa Running on October 17, 2026.

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 across local parks with increasing distances, chip timing, and series awards for runners who complete all four events. Entrants must be 15 or older and registration is online only.

Trail races at Bear Creek Lake Park on Oct 25 2026 featuring 5 km, 15 km, a 5+15 double and a Kids 1 km. Mostly dirt single and double track with steep climbs, marked courses and included postrace items for adult distances.

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 across local parks with increasing distances, chip timing, and series awards for runners who complete all four events. Entrants must be 15 or older and registration is online only.

Experience 13.1 miles of singletrack trails and hills in the Highlands Ranch Backcountry Wilderness Area. Enjoy custom medals and a post race pancake breakfast while competing for cash prizes in various categories.

Timed 6-, 12- and 24-hour running and relay events on a certified 1.0002 mile dirt loop at Colorado Youth Outdoors Swift Ponds in Fort Collins, with full-service aid every lap and locker-style lodge support nearby.

Trail races at Starsmore Visitor & Nature Center on November 8, 2026, with chip-timed 4-mile and untimed 2.5-mile courses on Columbine Trail; proceeds support Friends of Cheyenne Cañon and leashed pets are allowed on the trail.

Trail races in Louisville, CO offer a half marathon, 10K and 5K on mostly dirt out and back courses with mountain views. The event features aid stations, limited onsite parking and a family friendly post race atmosphere.

A four-race trail series across local parks with increasing distances, chip timing, and series awards for runners who complete all four events. Entrants must be 15 or older and registration is online only.

A winter trail event in Colorado Springs offering 50k, half marathon, and 10k courses that start at Bear Creek Regional Park. Trails include historic High Drive and Gold Camp Road with stocked aid stations and crew accessible points.