Trail Running calendar near Windsor 2026-2027

A multi-distance running event on a flat 1.05-mile loop in Longmont, Colorado, held September 11-12, 2026, honoring 9/11 with in-person and virtual options, race awards, on-course aid, and overnight food service.

A longstanding Nederland, Colorado running event offering a 5K road run, a 10K trail, and a trail half marathon, with family-friendly features, on-leash dogs allowed in the 5K, and costume encouragement.

A high altitude trail event in Granby, CO offering 50K, 33K, half marathon, 10K and 5K courses on dirt trails with measured elevation gain and support stations.

A 13.5 mile trail half around Lory State Park near Fort Collins with about 2,000 feet of climb, marked singletrack, aid stations, and a free one mile kids race.

Trail ultramarathon in Empire, Colorado on September 12, 2026 offering point to point 50K and 22K courses. High altitude routes reach over 13,000 feet and prior ultra or high altitude trail experience is required or recommended.

A mountain road race in Jelm, Wyoming with a 10 mile out and back on jeep roads and a 50k that repeats the loop three times. The course gains over 2,000 feet and reaches the Infrared Observatory above 9,600 feet.

A trail race in Golden, CO featuring a 10-mile North Table Loop with bonus miles and a 5-mile route on Lithic Trail and Fairmount Canal Loop. Organized by BeyondHome to support families moving from homelessness to self-sufficiency.

Expo Park XC is an old school grass cross-country meet in Aurora, Colorado, featuring creek crossings, a wooden footbridge and bale jumps. Races range from about 1 km for young children to a 5 km open race.

Experience the wild spaces of Northern Colorado with a weekend of trail races ranging from a half marathon to a 50 mile ultra through scenic forests and scout camp trails. Stay on site with available camping and community meals.

A two-day trail and bike event in Estes Park featuring 31-mile bike and run options, a 15-mile heavy half, and a 62-mile duathlon, with rugged trails, significant climbs, and aid stations supporting competitors.

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 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 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.

Trail races near Sedalia, Colorado on October 17, 2026 with 50 mile, 55k, 15 mile and 5 mile options through montane forests and red rock terrain. Limited field size, aid stations, drop bag access, camping by reservation, and specific pacer..

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.

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.