Colorado
Colorado Trail Running Calendar 2026-2027
Explore the best trail runs in Colorado for 2026-2027! Our updated list features 145 exciting trail runs across the region. Find your next trail run in Colorado below and join the trail community at these great events!
October 2026
Trail races at Bear Creek Lake Park with 5 km, 15 km, a 5+15 double, and a Kids 1 km; mostly dirt single and double track with marked courses and an aid station on the 15 km.
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 13.1 mile trail race through the Highlands Ranch Backcountry Wilderness in Douglas County with cash prizes and participant race amenities including a shirt, medal, and pancake breakfast.
Halloween themed 5k and 10k through historic downtown Erie and Coal Creek trails, with a kids Goblin Run and BOLDERBoulder qualifying times.
A backyard ultra at Bear Creek Lake Park where runners repeat a 4.167 mile loop every hour until one remains, up to 11 laps, with a 50 runner field cap.
A cross-country meet in South Boulder offering 1K, 3K and 5K races as Race 2 of the Boulder XC series at Harlow Platts Community Park.
November 2026
A four-race trail series in Colorado Springs with increasing distances, chip timing, and awards for runners who complete all four events.
Trail ultramarathon in Fruita Colorado with multiple distances on singletrack through high desert terrain and significant elevation change.
USATF certified one mile dirt loop at Swift Ponds in Fort Collins offering 6, 12 and 24 hour and relay options on Nov 7 and 8, 2026.
Six-hour timed loop at Sandstone Ranch in Larkspur, CO on an ~8-mile loop with about 765 ft gain and aid roughly every four miles.
Lap based 6 hour and 12 hour trail events near Mancos CO on a rugged one mile loop with individual and team divisions and a Hot Lap prize.
Trail runs from Starsmore Visitor and Nature Center in Colorado Springs, featuring a chip timed 4 mile course and a 2.5 mile out and back, with proceeds to Friends of Cheyenne Cañon.
Trail races in Louisville, Colorado on November 14, 2026 offering 13.1 miles, 10K and 5K out-and-back courses on dirt trails with aid stations and drop bag service.
Trail races in Loveland CO on November 14 2026: a just over 15K loop with a five hour limit plus a shorter 5K on mixed terrain.
A four-race trail series in Colorado Springs with increasing distances, chip timing, and awards for runners who complete all four events.
A 50K looped ultra near Golden, CO visiting four peaks from Parfet Park with an unmarked, self supported course and no entry fee.
Trail-run event in Colorado Springs on November 21, 2026 offering 50k, half marathon and 10k with dirt trails, stocked aid stations, and significant elevation.
A four-race trail series in Colorado Springs with increasing distances, chip timing, and awards for runners who complete all four events.
A family-friendly 5K in Buena Vista with a stroller-friendly trail course, a free kids fun run, local food pantry donations, and participant awards.
A fundraising 5K in Colorado Springs along the Pikes Peak Greenway Trail supporting CSAHA, with awards, participation medals, and concessions.