Colorado
Colorado Trail Running Calendar 2026-2027
Explore the best trail runs in Colorado for 2026-2027! Our updated list features 142 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
A four-race trail series across Colorado Springs parks with increasing distances, chip timing, and gift card awards for runners who complete all four events.
Single-loop trail event in Cañon City with river and tunnel sections, high alpine views, extensive singletrack, and multiple distances including 50k and 35 mile.
A traditional Backyard Ultra at Luvin Arms Animal Sanctuary on October 24-25, 2026 with hourly 4.167 mile loops, on-site aid, camping, and proceeds supporting the sanctuary.
Trail events at McGraw Memorial Park include a 2 mile course and a 12.6 mile endurance race made of six repeated 2.1 mile loops with decreasing lap times.
An approximately 18 mile trail across Boulder's five peaks with about 5,000 ft of climbing on October 24, 2026; limited to 100 participants with a $25 fee donated to recovery.
Trail races at Bear Creek Lake Park on October 25, 2026 offering 5K, 15K, a 5+15 double and a kids 1K, organized by Run Uphill Racing.
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 across Colorado Springs parks with increasing distances, chip timing, and gift card 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.
Timed 24, 12 and 6 hour events on a USATF certified one mile dirt loop at Swift Ponds in Fort Collins with full aid, medical coverage and relay options.
VO2Max 3K OCR in Colorado Springs on Nov 7, 2026 features an indoor/outdoor 3K course with 15 to 20 obstacles and finisher medals and t shirts.
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.