Trail Running Calendar Colorado 2025-2026

Welcome to Colorado's premier trail running calendar for 2025-2026! Recognized as a trail runner's haven, Colorado seamlessly blends bustling urban settings with pristine mountain terrains. Whether you're a native, a newbie, or a visitor exploring the Centennial State's running trails, our calendar ensures you don't miss out on any event.

Denver, the renowned Mile High City, beckons runners with its urban-meets-nature charm. Iconic routes like the Cherry Creek Trail zigzag right through the city's pulse. Venturing south, Colorado Springs, dubbed the "Olympic City", boasts of trails skirting the monumental Garden of the Gods. Here, a run transcends the ordinary, offering an experience akin to striking gold.

For those seeking a quiet escape, Aurora presents peaceful reservoir paths, making urban detox achievable. If the allure of academic vibes mixed with nature captivates you, Fort Collins and its famous Horsetooth Reservoir trails won't disappoint. Meanwhile, Lakewood introduces runners to nature's canvas with the Red Rocks painting every run. And let's not forget Boulder, offering a diverse range of trails set against the stunning backdrop of the Flatirons.

The Barr Lake Trail Race, taking place in Brighton, Colorado, on June 14, 2025, is a celebrated running event now in its sixth year. It features one of Colorado's flattest and fastest courses, with minimal elevation gain, making it ideal for both seasoned runners and newcomers. Participants can choo..

Estes Park's Backyard Ultra is a unique ultra-running event set against the stunning backdrop of Lake Estes, Colorado. Participants must complete a distance of 4.252 miles within one hour, every hour, until only one runner remains. This format continues indefinitely, with the last runner standing be..

Ring the Springs is an exhilarating trail running event set in the stunning landscapes of Colorado Springs, Colorado. Scheduled for June 21, 2025, participants can choose from three challenging distances: 100K, 50K, or 30K. The race begins and ends at the historic Rock Ledge Ranch in the iconic Gard..

The San Juan Solstice 50 Mile Run is an annual ultra-marathon held in Lake City, Colorado, typically around the Summer Solstice. Established in 1995, the event has evolved into a community benefit for local EMTs. The race features a challenging course that includes high mountain terrain and varying..

The Howelsen Hill Trail Run is a challenging trail running event set in the scenic surroundings of Howelsen Hill in Steamboat Springs, Colorado. Participants can choose between two distances: an 8-mile and a 4-mile course, both featuring beautiful single-track trails adorned with aspen trees and wil..

The Sunset Trail Running Festival, taking place in Gold Hill, Colorado, features a variety of trail races including a 28K, 12K, 5K, and a Kids 1K. This event, organized by The Boulder Watershed Collective and T.E.A.M Boulder, aims to raise funds for wildfire preparation and community resilience init..

The Leadville Trail Marathon and Heavy Half is a challenging running event held in the historic mining district of Leadville, Colorado. Participants can choose between a 26.4-mile marathon or a 15.4-mile Heavy Half, both featuring stunning alpine trails and reaching elevations over 13,000 feet at Mo..

The Timberview Trail Run is a scenic trail running event held at Lory State Park in Colorado, featuring three race distances: 5K, 5 Mile, and 10 Mile. Scheduled for June 28, 2025, this event caters to athletes of all levels, including beginners and families, with a beginner-friendly 5K route. Partic..

The John Cappis is a challenging mountaineering event held in Silverton, Colorado, honoring John Cappis, a co-founder of the Hardrock 100. Participants tackle an unmarked, off-trail course that spans approximately 50 kilometers with a staggering elevation gain of 19,000 feet, navigating rugged terra..

July 2025

The Hahns Peak Vertical Trail Race is an exhilarating 8-mile out-and-back trail run held annually at Hahns Peak in North Routt County, Colorado. Established in 2017, this challenging race features a steep ascent to the summit, reaching an elevation of 10,839 feet, with stunning panoramic views. Part..

The Vail Hillclimb will take place in Vail on Saturday 5 July 2025.

The Alma Foundation Race in the Clouds Dirt Festival is an exciting outdoor event taking place in Alma, Colorado, from July 10 to July 13, 2025. Set at an elevation of 10,600 feet, the festival features a variety of activities including mountain bike racing, trail running, a free kids' race, and an..

Chase the Moon is an exciting 12-hour endurance running event taking place in the Highlands Ranch Backcountry trail system. Participants can choose to run solo or form teams for a relay, with options for 3-person and 5-person teams. The race begins at sunset and continues through the night, illumina..

The Silverheels Trail Runs, part of the Human Potential Running Series, is an annual event taking place in Como, Colorado, featuring a variety of challenging distances including 10-Mile, 19-Mile, 60k, 50-Mile, 100k, and 100-Mile races. Set at an average elevation of over 10,000 feet, the course offe..

The Hardrock 100 is a challenging 100-mile ultramarathon held in the San Juan Mountain Range of Southern Colorado. Participants face a total elevation change of 66,394 feet, with an average elevation of over 11,000 feet. The course features a mix of 4WD roads, dirt trails, and cross-country sections..

The Leadville Silver Rush 50M is a challenging 50-mile trail run that tests participants' endurance and grit against the stunning backdrop of the Rocky Mountains. Set in Leadville, Colorado, the course features approximately 8,000 feet of elevation gain, taking runners through historic mining distri..

The Ouray 100 Mile Endurance Run is a challenging ultramarathon set in the breathtaking San Juan Mountain range of Colorado. Participants will face approximately 41,862 feet of elevation gain, making it one of the toughest endurance events. The race features stunning views and demanding climbs, culm..

The High Lonesome 100 is a challenging 100-mile trail race set in the stunning Sawatch Range of the Colorado Rocky Mountains. Participants will experience a grueling course featuring 23,500 feet of vertical gain, reaching elevations of 13,100 feet. The race includes a loop that traverses beautiful s..

The Spring Creek Memorial Trail Run is a scenic running event held in Steamboat Springs, Colorado, featuring a 9.5-mile loop and a 5K course. The race takes place on the picturesque Spring Creek trail, surrounded by wildflowers and Aspen trees, and includes challenging terrain with significant eleva..

The Audi Power of Four Trail Run is an exciting running event set in the scenic mountains of Aspen Snowmass. Participants can choose from three different race distances: a challenging 50K, a 25K, and a 10K run, catering to various skill levels. This event not only offers a chance to enjoy the beauti..