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.

Run The Ranch is an exciting trail running event taking place from April 1 to April 5, 2025, in Loveland, Colorado, at the Sylvan Dale Guest Ranch. Participants can choose from various distances, including a 5K, 10K, and multiple timed trail runs ranging from 4 to 12 hours, with options for solo and..

The Desert RATS Trail Running Festival by UTMB offers an exciting weekend of trail running in the stunning landscapes of Fruita, Colorado. With four unique race distances, including 100K, 50K, 21K, and 10K, the festival caters to both novice and experienced runners. Participants can enjoy breathtaki..

UTMB Index

The Can't Be Mad Running Festival, taking place in Erie, CO, offers a variety of running events including a 10K, 5K, a 3-hour timed event, and a Kid's 1K, with both in-person and virtual options available. The course features a flat and fast off-road cross-country style route, showcasing stunning vi..

The Rock Hawk Trail Races, part of the Bear Chase Race Series, take place on April 19, 2025, at Phillip S. Miller Park in Castle Rock, Colorado. This event features multiple race distances, including 50K, 25K, 10K, and 5K, catering to both novice and experienced trail runners.The scenic trails offer..

The Great Western Trail Race, taking place in Severance, Colorado, features a variety of running events including a 5K, 10K, half marathon, and a Kids Fun Run. This event celebrates Northern Colorado's newest trail, connecting Windsor, Severance, and Eaton. Participants can enjoy a festive atmospher..

The Rattler Trail Race, taking place in Colorado Springs, features three race distances: 50K, 25K, and 10K. Set in the scenic Palmer Park, participants will experience breathtaking views of the city and Pikes Peak while navigating technical trails with unique rock formations. The course is designed..

The Royal Gorge Groove is an exciting trail running event taking place in Cañon City, Colorado, on April 26, 2025. Participants can choose from various distances, including 50K, 30K, 20K, 12.5K, 5K, and a Kids Run, all starting and finishing at the scenic Royal Gorge Ranch & Resort. Runners will exp..

The Cheyenne Mountain Trail Race, taking place in Colorado Springs, CO, features multiple race distances including 50K, 25K, 7 Miler, and 4 Miler. Set against the stunning backdrop of Cheyenne Mountain State Park, participants will navigate scenic trails that include grassy meadows and wooded areas...

May 2025

The Greenland Trail Races, held annually in May at the Greenland Open Space in Larkspur, Colorado, features four race distances: 4 miles, 8 miles, 25K, and 50K. This event is known for its scenic trails with views of Pikes Peak, making it a popular choice for both novice and experienced runners. Par..

Take 5 in the Garden is an exciting running event held in the picturesque Garden of the Gods in Colorado Springs, CO. Participants can choose between a road race or a trail race, with options including a 5K, 5 Miler, and a 9.5-mile course. The event features closed roads, allowing runners to enjoy t..

The Collegiate Peaks Trail Run, celebrating its 35th anniversary, is a renowned trail running event held in Buena Vista, Colorado. Participants can choose between two challenging distances: 25 miles and 50 miles. Established in 1991, the race features a scenic course that follows single-track and je..

The Falcon 50 is an annual race series held on May 3, 2025, at the USAF Academy in Colorado Springs, featuring five race options: 50 Miler, Marathon, Military Heavy, Half Marathon, and Military Half-Heavy. Established in 2011, the event showcases scenic and challenging terrain, primarily on dirt tra..

The Quad Rock 50 and 25 Mile Trail Races, organized by Gnar Runners, will take place on May 10, 2025, in Lory State Park and Horsetooth Mountain Park, near Fort Collins, Colorado. This challenging event features a scenic course with significant elevation gains—over 5,500 feet for the 25-mile race an..

Niwot's Challenge is a challenging ultramarathon held in Colorado's Front Range, designed for experienced runners. Modeled after the Barkley Marathons, this grassroots event features a secretive course that requires participants to navigate primarily off-trail using a map and compass. The event incl..

The Mountain Ridge Trail Race, taking place on May 10, 2025, in Highlands Ranch, Colorado, offers a variety of distances for trail running enthusiasts, including a 21-mile, half marathon, 10K, and 5K. Celebrating its 11th year, the race features scenic dirt and single-track trails with manageable el..

The Valkyrie Trail Race is a women's-focused running event held in Cheyenne Mountain State Park, Colorado Springs. Participants can choose from various distances, including 4 miles, 30K, marathon, and up to 50K. The race features a scenic course that begins on crushed limestone and transitions to si..

Adventure Fest at 18 Road is an exhilarating weekend event in Fruita, Colorado, celebrating outdoor sports and community. Scheduled for May 10-11, 2025, the festival features a variety of activities including the Fruita Trail Half Marathon, Sarlacc Attack 50K mountain bike race, and The Dirty Edge G..

The Fruita Trail Half Marathon is an exciting 13.8-mile race set in the stunning desert landscape of Fruita, Colorado. Scheduled for May 11, 2025, this event features a loop course with beautiful singletrack trails, short climbs, and breathtaking views of the surrounding buttes and mesas. As part of..

The Ram Party Trail Runs, scheduled for May 17, 2025, in Colorado Springs, CO, offers a variety of race distances including 55 Mile, 60K, 50K, 24K, and 15K. Set against the stunning backdrop of Rampart Reservoir and Pikes Peak, participants can enjoy breathtaking views while challenging themselves o..

The Vallecito Lake Heavy Half is a scenic half marathon set around the picturesque Vallecito Reservoir in Colorado's San Juan Mountains. Scheduled for May 17, 2025, this unique race offers participants the chance to run on a course that includes sections typically closed to the public, such as a por..