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 Great Trailhead Foot Race 10 Miler takes place at Bear Creek Lake Park in Lakewood, Colorado, offering 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. Reg..

Beware The Bear Trail Races take place at Bear Creek Lake Park in Lakewood, Colorado. The event offers four distances: 5K, 15K, a 5K+15K double, and a Kids 1K race. The courses are mostly dirt, using single and double-track trails with short, steep climbs, rollers, and rugged terrain, providing a so..

Bridge Burner Ultra is a scenic, late-season race based in Canon City, Colorado, offering multiple distances: 35 miles, 50K, 35K, and 10K. The single-loop course runs along the Arkansas River, through historic Tunnel Drive tunnels, and climbs to 7,109 feet for sweeping views of the Royal Gorge, Sang..

November 2025

The Colleen De Reuck XC Classic is a cross country running event held annually at Harlow Platts Community Park in Boulder, Colorado. Honoring renowned distance runner Colleen De Reuck, the race promotes health, fitness, and celebrates local Olympians, with 2025 honoring 2012 Olympic marathoner Yoshi..

Colorado 24 Hour Run takes place in Fort Collins, Colorado, at 4927 E. County Road 36. The event offers multiple distance options: 24-hour, 12-hour, and 6-hour races, plus 24-hour, 12-hour, and 6-hour relays.Runners complete laps on a one-mile dirt loop—the flat, scenic loop you’ll find in Colorado—..

Bingo! Trail Party, hosted by the Human Potential Running Series, takes place at May Farms in Byers, Colorado. It features five levels: Level 1 (6–10 miles), Level 2 (8–20 miles), Level 3 (10–42 miles), Level 4 (10–54 miles), and Level 5 (18–54 miles), with a 9 PM time limit and a 300-runner cap. Th..

The HRCA Backcountry Wilderness Half Marathon is an annual 13.1-mile trail race held in Highlands Ranch, Colorado, featuring a scenic single-loop course through the Douglas County East/West trail and the Backcountry Wilderness Area. The race offers a challenging route on dirt, gravel, and singletrac..

Kessel Run Ultra takes place in Fruita, Colorado, just a short drive from the Front Range. The event offers five distance options: 50 Miler, 40 Miler, 50k, 20 Miler, and 10 Miler. It’s promoted as a Racecation Adventure and is renowned for world-class single-track in Fruita, with trails that reward..

Louisville Trail Race returns to Louisville, Colorado at Louisville Community Park. It offers three distances: Half-Marathon (13.1 miles), 10K (6.2 miles), and 5K (3.1 miles). The mostly dirt courses traverse scenic Front Range trails with views of the Flat Irons and a couple defining climbs, run as..

Colorado Cold Rush Ultra, held in Colorado Springs, offers 50K, half marathon, and 10K options. The race is billed as the "coolest" winter running event and features a route starting at Bear Creek Regional Park, climbing High Drive, and threading through tunnels from the Colorado gold rush along Gol..

December 2025

The Sawmill Trail Runs is an annual trail running event held at Staunton State Park in Pine, Colorado, approximately 40 miles southwest of Denver. The race offers three distance options: 8-Mile, 16-Mile, and 50k, with a combined runner capacity of 250. The course features scenic and challenging terr..

Thumbs Up Vertical Challenge takes place in Estes Park, Colorado, on December 6, 2025. The race uses the Thumb Open Space trail, a 2km out-and-back course with 540 feet of vertical gain per lap. The route is 100% single-track with switchbacks, steps and steep rocks, offering views of Longs Peak, Mou..

January 2026

The USCSA Cross Country Ski Racing Festival, hosted by Colorado Mesa University, takes place at Snow Mountain Ranch Nordic Center in Granby, Colorado. Scheduled for January 24-25, 2026, this event features collegiate and junior racers competing in classic and skate sprint races. Distances include 15..

February 2026

Gothic Mountain Tour takes place in Crested Butte, Colorado. It features two ski races: a 23.5-mile competitive course and a 17.85-mile recreational route around Gothic Mountain, finishing on the Crested Butte Nordic trail system at the Magic Meadows Yurt. The course begins in Crested Butte (competi..

Stories Trail Runs is a winter trail racing festival at Cheyenne Mountain State Park in Colorado Springs, CO, offering a scenic, community-focused atmosphere with views of Cheyenne Mountain, Pike’s Peak, and the Front Range. The weekend includes 6-Hour and 15-Hour timed events, plus traditional 10k,..

March 2026

The 21st Annual Run Through Time Trail Marathon and Half Marathon takes place in Salida, Colorado. It offers a Trail Marathon, a Trail Half Marathon, and a 2 Mile Run, plus a free kids’ 400-meter dash in Riverside Park. Courses run on the Arkansas Hills Trail System—dirt/jeep roads and narrow, hilly..

April 2026

Race The Ranch is a winter snowshoe race held in Granby, Colorado on the Snow Mountain Ranch YMCA property. It offers three distances: 5k (1 lap), 25k (2 laps), and 50k (4 laps), designed to accommodate runners of all levels. The course combines singletrack, doubletrack, and groomed snowshoe trails,..

Run the Ranch is an annual trail running event held at the scenic Sylvan Dale Guest Ranch in Loveland, Colorado. The race offers a variety of distances including 5K, 10K, and timed trail runs of 4, 6, and 12 hours, with options for solo runners and 4-person relay teams. Participants run on private r..

The Desert Rats Trail Running Festival will take place in Fruita from Friday 10 April 2026 to Sunday 12 April 2026. You can run between 9 and 100 kilometers.

UTMB Index

The Rattler Trail Race, held in Colorado Springs at Palmer Park, offers runners a chance to experience scenic singletrack trails with panoramic views of the city and Pikes Peak. The event features multiple distances: 50K, 25K, 10K, and 5K, catering to various skill levels. The course is known for it..