Trail Running Calendar Colorado 2025-2026

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.

High Five 100 is a self guided mountain challenge from Lake City, Colorado: roughly 90 to 105 miles with about 40,000 ft of climbing and summiting five 14ers. Finish the unmarked route within 48 hours; registration opens January 1, 2026.

Run the Rockies Trail in Frisco, Colorado offers 5k, 10k and half marathon on scenic single track and dirt trails. Take in views of Dillon Reservoir and the Ten Mile Range with a lakeshore finish to cheer your arrival.

Experience the Emerald Mountain Epic, a two day trail festival in Steamboat Springs where bikers and runners enjoy scenic singletrack through meadows and aspens. Fields are capped at 500 per day and proceeds benefit local youth and riders.

The Leadville Trail 100 Run is a legendary 100 mile ultramarathon in the Colorado Rockies that tests runners at high altitude with climbs to Hope Pass and sweeping mountain trails. Iconic belt buckles await finishers who make the 25 or 30 h..

Run scenic dirt roads and trails above 8,700 feet in Fraser, Colorado with a half marathon or 5K option. Enjoy a pre race gathering at Vicious Cycle Brewing and help the Shining Stars Foundation support families affected by cancer.

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.

Epic point to point ultramarathon from Mt Crested Butte to Aspen across the Elk Mountains. Tackle 40 miles and over 6,000 feet of climbing on high alpine terrain while supporting Crested Butte Nordic.

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.

Run Rabbit Run in Steamboat Springs Colorado is a rugged trail ultramarathon with 50 mile and 100 mile options that climb high alpine terrain. Limited fields, major prize money and charity support draw elite and adventurous runners.

Enjoy a challenging 13 mile trail run in breathtaking Ouray, Colorado, starting and finishing at Fellin Park. This community fundraiser supports the Ouray School and helps fund student trips, with free entry for local students and staff.

Race to the summit of Pikes Peak on the historic Barr Trail in Manitou Springs, Colorado. Choose the full marathon up and down the 14,115 foot peak or the uphill Ascent for an epic alpine challenge and unforgettable views.

Race to the summit of Pikes Peak on the historic Barr Trail in Manitou Springs, Colorado. Choose the full marathon up and down the 14,115 foot peak or the uphill Ascent for an epic alpine challenge and unforgettable views.

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.

Run the Rainbow Trail through the Sangre de Cristo mountains near Westcliffe Colorado at the Sangre de Cristo Trail Festival on September 26 to 27 2026. Distances from 8 mile to 100 mile offer a scenic weekend with a vibrant trail community..

Crested Butte Ultra offers high alpine single track racing in Colorado with 50 Mile, 55K and 35K options through Gunnison National Forest. Expect sweeping mountain ridge views, cupless aid stations, custom swag and a finisher buckle.

Run rolling single track and forest roads around Buena Vista, Colorado, with sweeping Collegiate Peaks views. Choose a 30K or 50K and soak up 14er Fest vibes with camping, live music and local vendors.

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.