Boulder Sunrise 5K/10K

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

The Boulder Sunrise 10k & 5k Run has a reputation of being one of the most scenic courses around. BBSC will provide runners with a supported course, including plenty of […]

Chase the Moon Trail Race

Mountain Vista High School 10585 Mountain Vista Ridge, Highlands Ranch, CO, United States

Chase the Moon is a 12-hour team relay and solo ultramarathon, run overnight under the light of the full moon in the Highlands Ranch Backcountry trail system (we promise some […]

Tri Boulder

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

‘The Beast’ Long Course distance will be back for its second year! As one of Colorado’s most popular summer triathlons, Tri Boulder offers many different multisport race distances, all in […]

Boulder Rez Marathon

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

The Boulder Rez Marathon is quickly becoming a Boulder classic! This isn’t just another run around the lake. September temperatures will create the perfect race atmosphere. BBSC will offer a […]

Rocky Mountain Tri-Fest

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

Rocky Mountain Tri-Fest is Colorado's newest Multisport event, catering to the whole family. With events for everyone from mom and dad looking to try their hand at a gravel triathlon, […]

Boulder Sunset Triathlon

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

Summer may be coming to an end, but our tri season is still heating up! Join us at the Boulder Reservoir for the 13th Annual Boulder Sunset Triathlon, a local […]

Boulder Sunset 5K/10K

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

The Boulder Sunset 10K & 5K Run is part of BBSC’s biggest endurance event of the summer. Spend your weekend racing with BBSC at the incredible and scenic Boulder Reservoir. Register, […]

Event Series Endurance Race Series

Westminster Trail Race

Wayne Carle Middle School 10020 100th Ave, Westminster, CO, United States

Join us at beautiful Standley Lake in Westminster for an unforgettable evening at the Westminster Night Trail! For its 12th year, this race takes on a whole new energy as runners […]

Grand Traverse Mountain Run

Mt. Crested Butte Mt. Crested Butte Ski Resort, Crested Butte, CO, United States

The Grand Traverse Mountain Run is a point-to-point ultra marathon from Crested Butte to Aspen, Colorado. The course follows the route of the Grand Traverse Backcountry Ski race. In total, […]

Please click here to submit your event for FREE to our online calendar.
We do not allow events without physical locations (IE – virtual runs, runs with locations TBD, etc…).
Please allow 48 hours after submission for an event to appear on the calendar. If you have already listed your event and would like us to update it, please contact us.