Boulder Peak Triathlon

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

The Boulder Peak Triathlon, Duathlon & Aquabike on July 10th is one of the countries longest and most well-known triathlons.  For the veteran or first time racer, this is THE […]

Greenland Pack Burro Race

Greenland Open Space 1532 E Noe Rd, Larkspur, CO, United States

Welcome to the annual Greenland Open Space Pack Burro Races presented by Double Rainbow Ranch! Grab your burro and join us for a fun and rewarding day on the majestic […]

High Lonesome 100

County Road 321 Nathrop, CO, United States

The High Lonesome 100 is a high flying endurance race in the Sawatch range of the Colorado Rocky Mountains. With 22,500' of vertical gain and reaching an elevation of 13,150', it's a hell of a course. The race runs in a loop through some of the most beautiful single track in the state, and takes runners on the Continental Divide and Colorado Trail, through 2 ghost towns, over 5 alpine passes, through remote basins, and over soaring ridges. This year's event takes place on July 30th.

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 […]

Audi Power of Four Trail Race

Aspen Mountain 601 East Dean Street, Aspen, CO, United States

The Audi Power of Four Race Series is a premier endurance race series utilizing the unique and amazing terrain of each of the four Aspen Snowmass mountains. Each race is […]

Summer Sizzler 5K/10K/15K

America the Beautiful Park Cimino Dr, Colorado Springs, CO, United States

Join us on July 15th, 2023 for the annual Summer Sizzler, featuring the amazing scenery of America the Beautiful Park!  Whether you are looking to run, walk or just enjoy […]

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 […]

Heritage Eagles 5K

Heritage High School 1401 W Geddes Ave, Littleton, CO, United States

Support the Heritage Eagles cross country team at the annual Heritage Eagles 5K. Last year's race, raised over $3,500 for the Heritage Eagles xc team; $ 10.00 of every registration […]

Spring Creek Memorial Trail Run

Spring Creek Trailhead Steamboat Springs, CO, United States

This race is held in memory of Patty Brenner Hagberg who was struck and killed by a truck along the lower part of the trail in 1991. This race should […]

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.