Trail Running calendar near Idaho Springs 2026-2027

OUTLAST Colorado Springs is a 6 hour trail challenge with a 5K lap every hour for six rounds. Patches and a medal are awarded for laps completed and finishers are ranked on a national leaderboard with cash prizes for top times.

A high alpine 50k near Mount Princeton in Nathrop, Colorado, featuring 7,000 ft of climbing and a 13,100 ft high point. The course follows Chalk Creek Canyon and the Colorado Trail through ponderosa and aspen forests to an alpine plateau.

A fall trail event in Buena Vista, Colorado on September 27, 2026 offering a 14K trail race with over 500 feet of elevation gain and a 5K along the Arkansas River. Both races start and finish at Vendor Village near the Eddyline Beer Garden.

A weekend trail endurance festival at Bear Creek Lake Park (Oct 3–4, 2026) offering distances from 5K to 100K on mostly singletrack, with looped courses, staffed aid stations, drop-bag access at the Start/Finish, and finishers' awards.

Experience the scenic HRCA Backcountry Wilderness Area with trail races for the whole family. Enjoy rolling hills and open views followed by a pancake breakfast and finisher medals for all participants in Littleton.

A Woodland Park trail event featuring 50k and 10k options on singletrack and forest roads with views of Pikes Peak, stocked aid stations, and crew access for the 50k.

A multi distance trail festival in Castle Rock featuring a family adventure run plus 5K, 10K, half marathon and 50K ultramarathon across Philip S. Miller Park and Ridgeline Open Space. Events include chip timing, finisher medals and aid sta..

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 6K trail run and walk in Aspen that welcomes dogs, offers timed results with cash prizes and costume awards, and donates net proceeds to the Friend of the Aspen Animal Shelter.

A four-race trail series across city parks with increasing distances, chip timing, and cumulative awards for runners who complete all four events.

A fall trail race at Staunton State Park offering 50K, 25K, a 25K FishSlappers division, and a steep 5K, run on runnable singletrack with aid stations and fundraising for land and water conservation.

An annual trail running event in Sedalia, Colorado offering 50-mile, 55k, 15-mile and 5-mile courses through montane forests, aspens, and red rock viewpoints, with limited camping, aid stations, and specific mid-race drop down and pacer rul..

Trail races at Palmer Park in Colorado Springs offering 50K, 25K, 10K and 5K with rocky bluffs and city views of Pikes Peak; courses are marked, aid stations serve most distances, and Aravaipa Running manages the event.

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 city and county parks with increasing distances, chip timed scoring, and series awards for runners who complete all four events.

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 across city and county parks with increasing distances, chip timed scoring, and series awards for runners who complete all four events.

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.