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 Sangre de Cristo Trail Festival, held near Westcliffe, Colorado, offers a rugged and scenic ultramarathon experience on the Rainbow Trail in the Sangre de Cristo Mountains. Participants can choose from distances including 8-Mile, 27k, 50k, 50-Mile, 100k, and 100-Mile, all running along the wilde..

The West Line Winder is a scenic trail running event held in Buena Vista, Colorado, featuring both 30K and 50K races. Set against the stunning backdrop of the Collegiate Peaks, participants can enjoy a mix of singletrack and forest roads, with significant elevation gain. This event caters to runners..

The Emerald Mountain Trail Run is a scenic running event taking place in Steamboat Springs, Colorado, featuring two race distances: a 12k (approximately 7.75 miles) and a 4-mile run. The course begins at the base of Howelsen Hill and winds through beautiful aspen-lined single tracks, making it a pic..

The Sawatch Ascent 50k is a challenging high-alpine trail race held in Nathrop, Colorado, showcasing the stunning Sawatch Range. Covering 33 miles with 7,000 feet of vertical gain, the course features a mix of 26 miles of singletrack, paved, and gravel roads. Starting and finishing at the base of Mo..

October 2025

The Hanging Flume 50K is an ultrarunning trail race held in Uravan, Colorado, starting and finishing at the historic Uravan Ballpark. The 50-kilometer course features a large loop that traverses abandoned mining two-track roads and scenic desert single-track trails near the confluence of the San Mig..

The Above The Clouds Ultra is an annual trail running event held in Woodland Park, Colorado, known as the "City Above the Clouds." It features two race distances: a 50K ultra and a 10K. The course showcases stunning Colorado fall colors and offers fast, flowing singletrack trails around Rampart Rese..

Rocky's Backyard Ultra is a unique ultra trail race held at the YMCA of the Rockies in Estes Park, Colorado, known as the highest organized Backyard Ultra in the world. Runners complete 4.167-mile laps on a challenging singletrack course featuring about 500 feet of elevation gain and loss per lap, w..

The West Elk Challenge is a scenic point-to-point trail marathon held in the North Fork Valley of Colorado, showcasing the peak fall colors of the West Elk Mountains. The 26.2-mile course starts at Crawford Reservoir State Park, traversing gravel roads through farms near Needle Rock before entering..

The Bear Chase Race is an endurance trail running festival held at Bear Creek Lake Park in Lakewood, Colorado. It offers multiple race distances including 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K, catering especially to first-time trail and ultramarathon runners. The course features mostly sof..

The Rim to Rim Royal Gorge Races is an exciting running event featuring a 5K road run, an 8-mile trail run, and a half marathon trail run, all set against the stunning backdrop of the Royal Gorge Bridge in Canon City, Colorado. Participants will experience challenging terrains and breathtaking views..

The Castle Rock Trail Festival, also known as the liveBIG Run, is an exciting trail running event held in Castle Rock, Colorado, featuring courses through the scenic Philip S. Miller Park and Ridgeline Open Space. It offers a variety of distances to suit all levels, including a 5K, 10K, half maratho..

The Pikes Peak Road Runners Fall Series is a challenging cross country trail running event held in Colorado Springs, Colorado. It features four races of increasing distances—3.8 to 7.4 miles—across diverse city and county parks including Bear Creek Terrace, North Monument Valley Park, Piñon Valley P..

The Suffer Better Fall Trail Run is an annual mountain endurance event held at Staunton State Park, Colorado. The 9th edition, scheduled for October 11, 2025, features multiple race distances including a challenging 50K, a 25K with a unique Fishslappers division involving fish catching, and a new 5K..

The Sage Burner Trail Race takes place in the scenic Hartman Rocks Recreation Area near Gunnison, Colorado, nestled in the Rocky Mountains. This fall event features challenging distances of 50K, 28K, and 15K, with the 15K supporting the Youth Trail Running Initiative to encourage young athletes. The..

The Indian Creek Trail Runs, part of the Human Potential Running Series, is an annual fall trail running event held at Indian Creek Campground in Sedalia, Colorado. Celebrating its 12th year, it offers multiple race distances: 5-Mile, 15-Mile, 55k, and 50-Mile, with time limits of 12 to 14 hours dep..

The Blue Sky Trail Marathon & Half Marathon, held in Fort Collins, Colorado, offers a scenic and challenging trail running experience through Horsetooth Mountain Park and Devil’s Backbone Open Space. The marathon covers 26.7 miles with 3,500 feet of elevation gain, while the half marathon spans 13.4..

The Bobcat Trail Race, held in Palmer Park, Colorado Springs, is a celebrated urban trail running event showcasing the park's rugged beauty and panoramic views of the city and Pikes Peak. Organized by Aravaipa Running since 2024, it offers four race distances: 50K, 25K, 10K, and 5K, catering to a ra..

The Great Trailhead Foot Race 10 Miler, held at Bear Creek Lake Park in Lakewood, Colorado, offers runners a scenic trail experience with single-track dirt paths against the backdrop of Denver's skyline. Participants can choose between a 5-mile or a challenging 10-mile double-lap course. Registratio..

The Bridge Burner Ultra is a scenic trail running event held in Canon City, Colorado, known as "The Climate Capital of Colorado." The race features multiple distances including a 35-mile loop, 50K, 35K, and 10K. The course begins along the Arkansas River, passing through historic granite tunnels on..

The Beware The Bear Trail Races, held at Bear Creek Lake Park in Lakewood, CO, offers a variety of race options including a 5km, 15km, and a kids' 1km run. The courses feature mostly dirt trails with a mix of steep hills and rolling terrain, making it suitable for both beginners and experienced trai..