Trail Running calendar near Boulder 2025-2026

The Pony Express Trail Run is a scenic trail race held at Rampart Reservoir, offering two distances: 8.5 miles and 16 miles. Participants enjoy running along well-marked single-track trails, crossing creeks, and observing wildlife amid Colorado's autumn landscape. The race emphasizes community and p..

The Red Feather Trail Jamboree is a three-day trail running event scheduled for September 26-28, 2025, in the scenic Red Feather Lakes region of Northern Colorado. Participants can choose from various distances, including a 50-mile race, a 50K, and a half marathon, all designed to be beginner-friend..

The 24 Hours Of Palmer Lake will take place in Palmer Lake from Saturday 27 September 2025 to Sunday 28 September 2025.

Rocky's Backyard Ultra is an exciting ultra trail running event held at the YMCA of the Rockies in Estes Park, Colorado. This unique race format challenges participants to complete a 4.167-mile loop every hour until only one runner remains. The course features stunning Rocky Mountain scenery, with a..

The Castle Rock Trail Festival, also known as the liveBIG Run, invites participants to challenge themselves on the scenic trails of Philip S. Miller Park and Ridgeline Open Space. This event caters to a wide range of athletes, offering various race options including a 5K, 10K, half marathon, and a 5..

The Bear Chase Race is an endurance festival held at Bear Creek Lake Park in Lakewood, Colorado, featuring a variety of race distances including 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K. Scheduled for October 4-5, 2025, this event is ideal for both novice and experienced trail runners, offerin..

The Above the Clouds Ultra is an annual running event held in Woodland Park, Colorado, featuring 50K and 10K races. Set against the stunning backdrop of Pikes Peak, participants can enjoy the vibrant fall colors and scenic trails around Rampart Reservoir. The race begins in the "City Above the Cloud..

The Blue Sky Trail Marathon and Half Marathon, scheduled for October 18-19, 2025, takes place in Fort Collins, Colorado, featuring scenic trails between Horsetooth Mountain Park and Devil’s Backbone Open Space. The marathon covers 26.7 miles with an elevation gain of 3,500 feet, while the half marat..

The Great Trailhead Foot Race features both a 10-mile and a 5-mile race, set against the scenic backdrop of Bear Creek Lake Park in Lakewood, Colorado. Participants can enjoy a mix of single-track and dirt trails while racing. Registration includes park admission, a post-race party with complimentar..

The Indian Creek Trail Runs, organized by the Human Potential Running Series, is a celebrated annual event taking place at Indian Creek Campground in Sedalia, Colorado. Known as the "Fall Classic," this race showcases some of the finest single-track trails in the Denver Metro area, allowing particip..

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..

The Colorado 24 Hour Run is an exciting endurance event taking place in Fort Collins, Colorado, featuring various race formats including 24-hour, 12-hour, and 6-hour runs, as well as relay options. Participants can challenge themselves to see how far they can run within their chosen time frame on a..

The Bingo! Trail Party is a unique running event organized by the Human Potential Running Series, set to take place at May Farms in Byers, Colorado. This fourth annual event encourages runners of all abilities to participate in a fun and community-oriented atmosphere. Participants run loops on a sce..

The HRCA Backcountry Wilderness Half Marathon is an annual trail race held in Highlands Ranch, Colorado, featuring a challenging 13.1-mile course that showcases stunning landscapes. Participants navigate through dirt, gravel, and singletrack paths, with opportunities to encounter local wildlife. The..

The Louisville Trail Race, celebrating its 12th year, features a Half Marathon, 10K, and 5K, set against the stunning backdrop of Louisville, Colorado. Known for its scenic trails and welcoming atmosphere, the race offers a mostly flat course with a challenging hill that rewards runners with breatht..

The Thumbs Up Vertical Challenge is an exciting running event taking place in Estes Park, CO, featuring an 8-hour ascent on the Thumb Open Space trail. Participants will complete an out-and-back course, collecting poker chips at the turnaround to determine their placing. Unique patches are awarded f..

The Sawmill Trail Runs, part of the Human Potential Running Series, is an annual trail running event held at Staunton State Park in Pine, Colorado. The event features three distance options: a 50k, a 16-mile, and an 8-mile race, catering to various skill levels. With a runner capacity of 250, the ev..

The USCSA Cross Country Ski Racing Festival is a premier event held at Snow Mountain Ranch Nordic Center in Granby, Colorado, scheduled for January 24-25, 2026. It features races for collegiate, high school, and middle school athletes, including classic and skate sprint events. The festival attracts..

The Winter's End Snowshoe Races, held at Granby Ranch Resort in Granby, CO, is an exciting winter running event that welcomes participants of all skill levels. Scheduled for March 7, 2026, the event features multiple race distances, including a marathon, 14-mile, 7-mile, and 5k, all set against the..