Event details subject to change. Please confirm all information via event website.
Sheep Mountain Ultras
Town of Fairplay Beach Beech Rd, Fairplay, CO, United StatesMake no mistake, the elevation profile for The Sheep Mountain 50 mile and 50k are docile looking. However, the average elevation of over 10,500’ and copious amounts of aggressive terrain, will see you waddle away from this race in shock. Come ready my friends, this mountain throws everything it has at runners, challenging you from […]
Stagecoach Gravel Triathlon
Stagecoach Reservoir 25500 Co Rd 14, Oak Creek, CO, United StatesWe didn't get the chance to launch this race in 2020, but that didn't diminish our passion for this brand new style of triathlon! To say this race is “unique” would be an understatement! Limited to just 250 athletes, we're excited to announce the first ever gravel triathlon to the Colorado triathlon landscape! This event […]
Boulder Stroke & Stride IX
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesThe Boulder Stroke & Stride enters its 24th season in 2025, and 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 reservoir dam on 8 Thursday evenings (plus one Wednesday evening) throughout the summer. Many participants make their open-water […]
Rocky Mountain Tri-Fest
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesRocky 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, to children looking to do their first triathlon. The Sprint and Super Sprint gravel Tris are beginner friendly with the bike course on the gravel […]
Outdoor Divas Triathlon
Union Reservoir 461 County Road 26, Longmont, CO, United StatesThe Outdoor Divas Sprint Triathlon on August 21st, annually awarded best women's event in Colorado by Competitor Magazine, is the all women's triathlon you've been waiting for! We intentionally keep the race cap low at 600 women to create a fun, festive, yet intimate racing environment. Great goodie bags, one of our biggest expos of […]
Rock Hawk Trail Race
Phillip S. Miller Park 1375 West Plum Creek Pkwy, Castle Rock, CO, United StatesHeld 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
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesSummer 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. […]
Boulder Sunset 5K/10K
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesThe 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.
Grand Traverse Mountain Run
Mt. Crested Butte Mt. Crested Butte Ski Resort, Crested Butte, CO, United StatesThe 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, runners travel 40 miles across the Elk Mountains with over 6,000′ of elevation gain.
PPRR Nielson Challenge
North Monument Valley Park 1794 Culebra Ave., Colorado Springs, CO, United StatesRace Format The first time you run this event, you'll establish a base time for yourself. This base time is used to generate a handicap time. The handicap time is calculated using an algorithm developed by Bob Royse, and it's geared to favor a beginning runner and the slower runners. Click here for an explanation of the […]
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.