Trail Running calendar near Windsor 2025-2026

The Summits Trail Runs, part of the Human Potential Running Series, take place at Granby Ranch Resort in Colorado's Rocky Mountains. This event offers multiple trail running distances: Single (6 miles), Double (21 miles), Triple (27 miles), and Quad (43 miles), plus a unique 32-hour Elevation Challe..

The Barr Lake Trail Race, held in Brighton, Colorado, offers a scenic and fast trail running experience around Barr Lake State Park. Celebrating its sixth year, the event features multiple distances: 50K, 30K, half marathon, 15K, and 5K, all on flat, dirt terrain with minimal elevation gain (under 1..

Estes Park's Backyard Ultra is a unique ultramarathon held in Estes Park, Colorado, featuring scenic views of Lake Estes. Participants run a 4.252-mile loop on a paved bike trail with a 150-foot elevation gain per lap at 7,522 feet elevation. The race follows the Backyard Ultra format, where runners..

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 Midsummers Night Run is a 10K race held in Winter Park, Colorado, starting and finishing at the base of Winter Park Resort. The course features a mix of gravel roads and trails with an elevation gain of approximately 570 feet, offering a scenic and moderately challenging route. This event is par..

The Timberview Trail Run is an annual trail running event held at Lory State Park in Bellvue, Colorado. Celebrating its sixth year in 2025, the race offers three distances: 5K, 5 mile, and 10 mile, catering to all levels of athletes including beginners and children. The scenic courses wind through f..

Chase the Moon is a unique overnight ultramarathon held in Highlands Ranch, Colorado, featuring a 12-hour solo and team relay format under the full moon. The event offers various distances including 12-hour solo, 3- and 5-person relays, 6-hour and 3-hour solos, and a 50K race. Runners traverse a sce..

The Never Summer 100km and 60km trail races take place in State Forest State Park, Colorado, between the Never Summer Mountains near Rocky Mountain National Park and the Medicine Bow Mountains north of Cameron Pass. The event offers ultra-distance mountain running with challenging terrain including..

The Elevation Run/Walk is an annual event held in Conifer, Colorado, featuring race distances of 10 miles, 5 miles, and 2 miles. Set at an average elevation of 8,200 feet, the course showcases the scenic Aspen Park neighborhoods, combining paved roads, dirt roads, and trail running. The event suppor..

The Boulder Rez Marathon, held at Boulder Reservoir in Boulder, Colorado, offers a scenic and mostly flat course with only 200 feet of elevation gain. Runners enjoy trails and dirt roads alongside the reservoir, with stunning views of the water and the Rocky Mountains. The event features multiple di..

The Lory Summer Trail Series is a fun, low-key trail running event held each Tuesday evening in August at Lory State Park, Fort Collins, Colorado. It features a series of shorter races with distances ranging from 5K to 12K, designed to welcome new trail runners and help experienced racers sharpen th..

The Eltuck Valley 5K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 5, 2025, this event is designed to cater to both novice and experienced runners, offering a flat and fast course ideal for those looking to improve their speed. Particip..

The Holy COW Trail Stampede is an exciting running event held in Westminster, Colorado, featuring a 10-mile race and 5K/10K options. Participants can enjoy a fun and festive atmosphere while supporting the charity partner, Growing Home, which focuses on breaking the cycle of poverty for families in..

The Med Bow Rail Marathon and Half Marathon, held in the scenic Medicine Bow National Forest near Laramie, Wyoming, offers runners a unique high-elevation challenge. The marathon covers the entire 21-mile Medicine Bow Rail Trail, averaging 8,926 feet in elevation, crossing briefly into Colorado befo..

Dirt Circus - Boulder is a free community running event held in Boulder, Colorado, celebrating local trail running culture. Organized by UltraSignup, this one-day festival features a social group run with options of a casual 4.5-mile or 10K route through local trails. The event fosters camaraderie a..

The Into the Hills Eltuck 10K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 12, 2025, this event is designed to cater to both novice and experienced trail runners, offering a challenging course with significant elevation gain and stunni..

The Into the Hills Eltuck 5K is part of a series of midweek trail races held at Lory State Park in Bellvue, Colorado. Scheduled for August 19, 2025, this event features a challenging course with a steep climb and descent, making it suitable for both novice and experienced trail runners. Participants..

The NoCo Urban Ultra & Relay is a long-distance running event taking place on August 22-23, 2025, along the scenic Poudre River Trail in Northern Colorado. Participants can choose from a 50-mile solo race, a 100-mile solo race, or relay options for both distances, accommodating teams of 2 to 8 runne..

The Byers Peak Stampede Half Marathon & 5K Run is an exciting running event set in the stunning Rocky Mountains, just 60 miles from Denver. Scheduled for August 23, 2025, the event features a challenging half marathon and a 5K, catering to athletes of all levels. The courses primarily traverse dirt..

The Staunton Rocks! Marathon & Half is a trail running event held at Staunton State Park in Pine, Colorado, in the Front Range Mountains southwest of Denver. The race offers two distances: a marathon (26.3 miles with 4,500 feet of elevation gain) and a half marathon (13.1 miles with 2,200 feet of ga..