Event details subject to change. Please confirm all information via event website.
Mountain Swim Series IV
Highest altitude organized marathon swim event in the country at ~8,000 feet. RACE DETAILS Distance Price* Swimmers 2.5K $110.00 Both skin/wetsuit event options 1-hour swim cutoff** 1 loop around the course 5K $130.00 Both skin/wetsuit event options 2-hour swim cutoff** 2 loops around the course 10K $150.00 Highest altitude organized […]
Ram Run 5K
Come join in the celebration of the resurgence of a great community event. The Ram Run will be returning to it's traditional month. This fun and exciting event will include a 5k around the neighborhoods near Green Mountain High School. Proceeds will help benefit the Green Mountain High School Cross Country Team. The first 150 […]
Boulder 5K Taco Run
Super charge your Taco Crushing appetite with a run before the Boulder Taco Fest! A non-competitive fun run on some of Boulder’s most beautiful multi-use paths. There’s even an aid station with some Boulder Taco Fest-themed treats. You’ll finish up back at the Boulder Taco Fest, ready to celebrate your run at Boulder’s favorite summer […]
Pioneer Prairie Dog Half Marathon
Westminster Promenade 10600 Westminster Blvd, Westminster, CO, United StatesWelcome to the Pioneer Prairie Dog Half Marathon event; the one that started the series! With 10k and 5k events too! Everyone is back to school and slipping into a routine. Make this your mental health break as you break away from the chaos of weekly schedules and give yourself a morning to race in […]
Wellington Swim-Run Challenge
Swimmers may choose to swim with their shoes, paddles, a wetsuit, pull buoy, floaties, rubber duckies, inflatable flamingoes or any other nonmotorized swim aid in this event. Race Course Per Lap = 0.3 M Swim, 1.6 K Run Total: 3 Laps = 1 Mile Swim, 5K Run
Eltuck Valley 12K
Lory State Park 708 Lodgepole Dr, Bellvue, CO, United StatesJoin us each Tuesday evening in August for a fun series of shorter midweek trail races. Our goal is to offer a fun, low-key series of races designed to give newer trail runners an opportunity to dip their toes into the trail racing waters, and to offer more experienced trail racers a chance to sharpen […]
Rock Hawk Trail Race
Held on the gorgeous, thrilling and rolling trails of Castle Rock’s Miller Park & Ridgeline Trail systems. While not overly technical, these trails will challenge and excite, as you soak up the amazing views. This is an excellent race for both first-time and veteran trail runners, and provides a nice test for those who are […]
Boulder Sunset Triathlon
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 favorite. For the 5th year in a row we are the proud host of the Mountain Collegiate Conference race and the USAT Duathlon Race Series. […]
RexRun 5K for PAWSitivity
The RexRun 5K is a 5K run/walk to spread mental health awareness and #PAWSitivity in schools with the help of more Therapy K-9's like Arapahoe County Sheriff's Office K-9 Rex. This year's event is at Dove Valley Park in Centennial on August 6th.
Boulder Sunset 5K/10K
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, and start training for the end-of-the-summer endurance festival with BBSC.
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.