Trail Running calendar near Denver 2026-2027

A trail race on the Frisco Peninsula offering 5k, 10k and half marathon courses with lakeshore finishes, chip timing, stocked aid stations, post-race food and beer, and marked single track and dirt trails.

A midweek trail race at Lory State Park, the 10 km course is part of an August series and features about 1,700 feet of elevation gain, chip timing, series points and postrace pizza and beverages.

A four‑week August trail race series at Lory State Park featuring 5K, 10K and 12K options with varied elevation. Post‑race pizza and beverages are provided and series awards go to top points scorers.

Run along Boulder Reservoir on flat, mostly dirt trail courses with sweeping Rocky Mountain views. Choose from 10K, 3 4 marathon, half, full marathon or relay, with USATF certified courses, a shirt and a finisher medal.

Roxborough Ultras features 50K and 50M all trail ultramarathons in Roxborough State Park with sustained climbing, technical terrain, and big elevation gain. August is hot and dry with limited shade and spaced aid stations, so carry water an..

Trail races at Cheyenne Mountain State Park feature 5K, 10K and a 25K summit course with about 3,450 feet of elevation gain; the 25K is a Pikes Peak Ascent qualifier and the event raises funds for park trail projects.

Run the scenic Leadville Trail 10K on August 16, 2026 in historic Leadville, Colorado, tracing the opening miles of the LT100 course at over 9,700 feet. Enjoy a fast out and back on paved and dirt roads with aid at the turnaround and awards..

A midweek trail 5k at Lory State Park in Bellvue, Colorado, presented as part of an August series. Chip timing, series points and awards, free vintage shirts for registrants, and pizza and beverages after each race.

A four‑week August trail race series at Lory State Park featuring 5K, 10K and 12K options with varied elevation. Post‑race pizza and beverages are provided and series awards go to top points scorers.

A 99.7 mile out and back ultramarathon in Leadville, Colorado, with 11 aid stations, high altitude passes near 12,526 feet, and belt buckle cutoffs at 25 and 30 hours.

Trail races in Fraser, Colorado on August 22, 2026, offering a Half Marathon and a 5K on unpaved roads and trails. Proceeds support the Shining Stars Foundation and dogs are allowed on leash.

The Staunton Rocks will take place in Pine Junction Area on Saturday 22 August 2026. You can run between 13 and 26 miles.

A four‑race August trail series at Lory State Park featuring 5k to 12k courses, chip timed results and series awards, with postrace food and beverage and vintage race shirts available to registrants.

Trail races on the Miller Park and Ridgeline trails in Castle Rock offering 50K, 25K, 10K and 5K with aid stations, drop bag support, chip timing and live split tracking; proceeds support local open space and trail efforts.

A family-focused trail event at Arapahoe County Fairgrounds on August 29, 2026, featuring a 5K run, a family 5K walk and a kids 1 mile run. The day includes dog demonstrations, a costume contest, auctions, vendors and a pancake breakfast.

A mountain trail race at Arapahoe Basin on September 5, 2026 covering *9.4 miles* and *2,211 ft* of ascent, with Sport, Expert and Pro divisions, a 700 runner cap, on course aid stations and category prizes.

A remembrance running event in Longmont, Colorado on September 11 and 12, 2026 featuring loop course races from 5K to 100 miles and a virtual option. The event includes aid stations, participant shirts, finisher awards, and on site food for..

Ned Ned Run in Nederland Colorado features a trail Half Marathon, a 10K on dirt roads and single track, and a 5K out and back near Old Town. The event is family friendly, allows leashed dogs in the 5K, and encourages costumes.

Snow Mountain Ranch in Granby Colorado features trail races from 5K to 50KM across dirt trails with varied elevation and mountain views. Loop courses include aid stations, drop bag access, onsite lodging, and a pacer option for the 50KM fin..

A 13.5 mile trail half around Lory State Park near Fort Collins featuring about 2,000 feet of climb, mainly singletrack terrain and a free one mile kids race. Post race breakfast and awards are held at the Soldier Canyon Picnic Area.