Trail Running calendar near Longmont 2025-2026

We have found 36 Trailruns within 80 miles of Longmont. See below where and when you can find the races.

Run under the full moon on Highlands Ranch trails in Chase the Moon, an overnight looped endurance event offering 12, 6 and 3 hour solos plus 50K and team relays. Enjoy scenic dirt trails, aid stations, and a festive night race atmosphere.

July 2026

Experience high altitude trail running July 10 and 11, 2026 around Como, Colorado with distances from 10 miles to 100 miles. Courses wind through alpine meadows, aspen groves and historic mining sites with sweeping views of South Park Valle..

Experience high alpine trails from Gould Colorado in the Never Summer range with 100 km and 60 km options. Rugged singletrack, big climbs and alpine lakes await for a true mountain adventure.

Take on the Summit 200, a breathtaking 200 mile loop around Summit County, Colorado that climbs above 12,700 feet and delivers about 40,000 feet of gain. Expect remote high altitude single track, sparse aid and an epic endurance challenge.

Join the Wild West Relay, a scenic point to point 200 miles across Colorado from Fort Collins to Steamboat Springs. Run solo or with teams from 1 up to 12 people as you tackle mountain passes, open roads and big western views.

August 2026

Run the Lory Summer Trail Series at Lory State Park in Fort Collins this August with four midweek trail races from a fast 5k to a testing 12k. Perfect for newcomers and speed seekers, with post race pizza, drinks, and series awards.

Run the Rockies Trail in Frisco, Colorado is a scenic 5k, 10k and half marathon on single track and dirt roads with views of Dillon Reservoir and the Ten Mile Range and a lakeshore finish. The half gets new single track in 2026.

Experience scenic high altitude trail running in Fraser, Colorado at the Byers Peak Stampede Half Marathon and 5K, a fundraiser for the Shining Stars Foundation. Tackle a challenging half above 9,500 ft or enjoy a dirt road 5K.

Choose from 50K, 25K, 10K or 5K on rolling singletrack and multiuse trails with sweeping views at Philip S. Miller Park in Castle Rock, Colorado. Portions of proceeds support Castle Rock open space and local charities.

September 2026

Front Range Ultra Dayze invites ultrarunners to a multi day looped trail festival along River's Edge in Loveland, Colorado, offering timed and distance events from 12 hour to 200 mile. Enjoy scenic two mile loops, around the clock aid, camp..

Challenge yourself on the Cirque Series at Arapahoe Basin on September 5, 2026 in Keystone, Colorado. This scenic 9.4 mile mountain course with 2,211 ft of climbing delivers steep, technical trail and big alpine views in a capped field.

Ned Ned Run in Nederland Colorado blends scenic trail and road running through the foothills, offering a half marathon, 10K and fun 5K for all abilities. Family friendly and costumes encouraged, with leashed dogs welcome in the 5K.

High alpine trail festival at YMCA of the Rockies in Granby, CO offering 5K to 50K races, plus Moosehead and Baby Moose challenge options. Expect dirt singletrack, big climbs and sweeping mountain views for all abilities.

Experience the Red Feather Trail Jamboree at Ben Delatour Scout Ranch with 50 mile, 50K and half marathon options across high elevation singletrack and technical mountain trails. Expect big views, wildlife and well stocked aid stations.

Push your limits in a community driven 24 hour endurance run on the scenic Palmer Divide near Palmer Lake, CO on Sept 26, 2026. Loop the 0.82 mile course, chase distance awards and support local parks with every entry.

October 2026

Run seldom used single track through Front Range montane forests and ridge viewpoints at Indian Creek. Distances from 5 Mile to 50 Mile and 55k offer something for every trail runner with limited field and rustic camping.