Trail Running calendar near Longmont 2025-2026

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

Chase the Moon is a unique 12-hour endurance run held in the Highlands Ranch Backcountry trail system, offering participants the chance to run solo or as part of a relay team under the full moon. The event features various race options, including solo runs of 12, 6, and 3 hours, as well as a 50K dis..

The Silverheels Trail Runs is an annual ultramarathon event held in Colorado's stunning Front Range, featuring distances from 10 miles to 100 miles. The race takes place at high elevations, with courses through alpine meadows, ghost towns, and mountain forests, offering spectacular views of Colorado..

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 a challenging ultramarathon scheduled for July 28, 2025, in Summit County, Colorado. It features a 200-mile loop through scenic mountain terrain, with over 40,000 feet of elevation gain and sections exceeding 12,700 feet altitude. The race emphasizes a small, intimate field limited..

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

The Boulder Rez Marathon is a scenic running event held at the Boulder Reservoir in Colorado, featuring a variety of race distances including a marathon, half marathon, 3/4 marathon, and 10K. The course primarily consists of dirt roads and trails, offering stunning views of the reservoir and the Roc..

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 ranging from 5K to 12K, with courses that vary in elevation and difficulty. The event aims to c..

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 is a scenic event featuring a 5k, 10k, and half marathon through the trails of Frisco Peninsula, offering stunning views of Dillon Reservoir and the Ten Mile Range. The courses include single track and dirt roads, starting and finishing at the Frisco Nordic Center. Par..

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..

Dirt Circus - Boulder is a vibrant community running event scheduled for August 9, 2025, in Boulder, Colorado. Organized by UltraSignup, this festival celebrates local races, run clubs, and businesses, fostering camaraderie among trail running enthusiasts. Participants can enjoy a social run with op..

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 and Half Marathon, scheduled for August 23, 2025, takes place in the scenic Staunton State Park, located in Colorado's Front Range Mountains. This event features a challenging yet accessible course, primarily on singletrack trails, allowing participants to enjoy breathta..

The Westminster Night Trail is an annual nighttime running event held at Standley Lake in Westminster, Colorado. Celebrating its 12th year, the race offers distances from 5K to 50K, all on scenic, packed dirt trails illuminated by lights and the stars. Participants enjoy stunning views of the lake a..

The Antelope Dash is a trail running event held at Curt Gowdy State Park in Wyoming. Participants can choose between an 8-mile and a 4-mile race, both featuring scenic routes through rolling hills, forests, and striking rock formations. The courses start at an elevation of 7,300 feet and ascend to 7..