Trail Running calendar near Boulder 2025-2026

The Summits Trail Runs, hosted at Granby Ranch Resort in Colorado, is an exciting trail running event that features a variety of distances, including ultra options. Participants can choose from courses ranging from 6 to 43 miles, all set against the stunning backdrop of the Rocky Mountains. The even..

The Barr Lake Trail Race, taking place in Brighton, Colorado, on June 14, 2025, is a celebrated running event now in its sixth year. It features one of Colorado's flattest and fastest courses, with minimal elevation gain, making it ideal for both seasoned runners and newcomers. Participants can choo..

Estes Park's Backyard Ultra is a unique ultra-running event set against the stunning backdrop of Lake Estes, Colorado. Participants must complete a distance of 4.252 miles within one hour, every hour, until only one runner remains. This format continues indefinitely, with the last runner standing be..

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 Timberview Trail Run is a scenic trail running event held at Lory State Park in Colorado, featuring three race distances: 5K, 5 Mile, and 10 Mile. Scheduled for June 28, 2025, this event caters to athletes of all levels, including beginners and families, with a beginner-friendly 5K route. Partic..

The Leadville Trail Marathon and Heavy Half is a challenging running event held in the historic mining district of Leadville, Colorado. Participants can choose between a 26.4-mile marathon or a 15.4-mile Heavy Half, both featuring stunning alpine trails and reaching elevations over 13,000 feet at Mo..

The Vail Hillclimb will take place in Vail on Saturday 5 July 2025.

The Alma Foundation Race in the Clouds Dirt Festival is an exciting outdoor event taking place in Alma, Colorado, from July 10 to July 13, 2025. Set at an elevation of 10,600 feet, the festival features a variety of activities including mountain bike racing, trail running, a free kids' race, and an..

Chase the Moon is an exciting 12-hour endurance running event taking place in the Highlands Ranch Backcountry trail system. Participants can choose to run solo or form teams for a relay, with options for 3-person and 5-person teams. The race begins at sunset and continues through the night, illumina..

The Silverheels Trail Runs, part of the Human Potential Running Series, is an annual event taking place in Como, Colorado, featuring a variety of challenging distances including 10-Mile, 19-Mile, 60k, 50-Mile, 100k, and 100-Mile races. Set at an average elevation of over 10,000 feet, the course offe..

The Leadville Silver Rush 50M is a challenging 50-mile trail run that tests participants' endurance and grit against the stunning backdrop of the Rocky Mountains. Set in Leadville, Colorado, the course features approximately 8,000 feet of elevation gain, taking runners through historic mining distri..

The 10K & 5K @ 10,000 Feet will take place in Vail on Saturday 19 July 2025. You can run between 5 and 10 kilometers.

The Never Summer 100km and 60km races will take place from July 25-27, 2025, in the stunning landscapes of State Forest State Park, Colorado. This challenging mountain race features a variety of terrains, including high alpine ridges, meadows, and rocky trails, with participants experiencing breatht..

The Summit 200 is an extraordinary 200-mile mountain race set in Summit County, Colorado, featuring a challenging loop that showcases stunning natural beauty. Runners will navigate a mix of hiking trails, forest roads, and paved sections, with elevations ranging from over 9,000 to nearly 13,000 feet..

The Berry Picker Trail Run will take place in Vail on Saturday 2 August 2025.

The Sheep Mountain Ultras, part of the Human Potential Running Series, is an annual trail running event held in Fairplay, Colorado. Scheduled for August 2, 2025, it features three race distances: a challenging 50-mile, a 50k, and a half marathon, all set against the stunning backdrop of the South Pa..

The Boulder Rez Marathon is a scenic running event held at the Boulder Reservoir in Colorado, featuring a flat course primarily on dirt roads and trails. Participants can choose from various distances, including a marathon, half marathon, 3/4 marathon, and 10K. The race offers stunning views of the..

The Lory Summer Trail Series, taking place from August 5 to August 26, 2025, offers a series of midweek trail races designed for both novice and experienced runners. Participants can choose from distances of 5K, 10K, and 12K, with courses that vary in elevation gain. The event aims to create a fun a..

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 Run The Rockies Trail Race offers a scenic running experience through the Frisco Peninsula trails, featuring a 5k, 10k, and half marathon. Participants can enjoy stunning views of Dillon Reservoir and the Ten Mile Range, making it an ideal course for both beginners and seasoned runners. The even..