Event details subject to change. Please confirm all information via event website.
Odell Brewing 5K
Odell Brewing Company 800 East Lincoln Avenue, Fort Collins, CO, United StatesJoin us for the Odell Brewing 5k, and great, local craft beer at Odell Brewing Company in Fort Collins on July 11, 2026 Join us for The Odell Brewing 5k […]
Heatwave Half Marathon
5K/10K/Half- Marathon & Relay registration includes a custom bib, designer shirt, and a custom finisher medal! 1 Mile registration is untimed and includes a custom bib, designer shirt, and a […]
Boulder Peak Triathlon
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 […]
RMRR Stone House 2M
Stone House Park 2800 S. Estes St., Lakewood, CO, United StatesEveryone – slow, fast, or in-between – can win at RMRR Trophy Series races. With our handicap scoring system, we predict YOUR finish time based on recent running results, giving you a great […]
Boulder Stroke & Stride VI
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesThe Boulder Stroke & Stride offers Boulder area athletes a fun 1-lap 750 Meter Swim, or 2-Lap 1500 Meter swim in Boulder Reservoir, followed by a 5k run on the […]
High Lonesome 100
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.
Ouray 100
With ~42k feet of gain for the 100 miler, this will be one of the most difficult things you ever attempt. Lucky for you, Ouray (dubbed the "Switzerland of America") […]
Audi Power of Four Trail Race
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 Splash Prairie Dog Half Marathon
Castle View High School 5254 N. Meadows Dr., Castle Rock, CO, United StatesWelcome to the Summer Splash Prairie Dog Half, 10k & 5k in Castle Rock, Colorado. Part of the Prairie Dog Half race series, join us in July as we race […]
Silverton Alpine Marathon
Experience the best of the San Juan Mountains with an 8 miler, a marathon, or a 50 kilometer run along the Alpine Loop past the historic mining ghost towns of […]
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.