Steamboat Lake Sprint Triathlon

Steamboat Lake State Park 61105 RCR 129, Clark, CO, United States

After last summer this event instantly became a personal favorite for our staff, volunteers, and athletes - come find out why!  We couldn't be more excited about this course, this lake, and the overall experience.  The swim starts out in the surprisingly warm waters of Steamboat Lake (74 degrees average race temp), then athletes transition […]

$85 – $135

Canceled Two Brothers Up-and-Down 5K/10K

Courtney-Ryley-Cooper Park 2350 Colorado Blvd, Idaho Springs, CO, United States

Run your slowest 5K, then turn around and run your fastest at the Two Brothers Up-and-Down 10K on August 28th in Idaho Springs. This race climbs 1,800' in 5K and then turns around and goes back down!

Boulder Stroke & Stride IX

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

The Boulder Stroke & Stride enters its 23rd season in 2024, 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 […]

BRR Summer Track Series #4

Potts Field 4001 Discovery Drive, Boulder, CO, United States

Join us for The Boulder Road Runners All-Comers Summer Track & Field series! We are back at CU Pott’s Field on a brand new track!! Fun for all, from newcomers of any age racing for the first time to veteran competitors looking to test their fitness, all in a friendly, welcoming environment. We host multiple […]

$10 – $15

Mile High Mile

Fairview High School 1515 Greenbriar Blvd, Boulder, CO, United States

Everyone can run the MILE! The 5th annual Mile High Mile is a high-energy event for runners of all ages and abilities. Big race atmosphere with a big expo, athlete introductions, and each wave has a chance to break the tape! Stick around to cheer the top competition under the stars and the lights of […]

First Fridays 5K

Festival Park 199 Perry St., Castle Rock, CO, United States

Friday nights in the summer are made for spending time close to home, enjoying the beautiful weather, and unwinding from the long week. Why go anywhere else but Downtown Castle Rock? Start the night off on the right foot with the First Fridays 5K. Before enjoying the free concert event, get a workout with the […]

Canceled Rocky Mountain 5K

Stanley Park 380 Community Dr, Estes Park, CO, United States

Escape to the mountains for some fresh air! With the Rocky Mountain Half Marathon, 5K, and Elk Double (half marathon + 5K) you can choose your own adventure! The Rocky Mountain Half Marathon and 5K courses both take place just outside Rocky Mountain National Park and start and end by the lake at the fairgrounds […]

Dirty Dozen Trail 10K

VIX Ranch Park 627 North Wildhorse Dr, New Castle, CO, United States

The New Castle Rides and Reggae Festival is a celebration of trail running, mountain biking, music and community. Join them for the Dirty Dozen Tail 10K on August 6th.

CMRA/RMRR 5K

deKoevend Park 6315 S. University Blvd., Centennial, CO, United States

Join us for the August Trophy Series race and picnic at deKoevend Park in Centennial.  This year our friends with the Colorado Masters will be joining us again for a great race and a fun post-race picnic!! We will be providing soda, seltzer, and chips. We ask that you bring your own picnic fare. We […]

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.