Event details subject to change. Please confirm all information via event website.
Week of Events
Sunday, August 23, 2026
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August 23, 2026 -Pioneer Prairie Dog Half Marathon
Pioneer Prairie Dog Half Marathon
Welcome 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 […]
Monday, August 24, 2026
No events on this day.
Tuesday, August 25, 2026
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August 25, 2026 -Eltuck Valley 12K
Eltuck Valley 12K
Join 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 […]
Wednesday, August 26, 2026
No events on this day.
Thursday, August 27, 2026
No events on this day.
Friday, August 28, 2026
No events on this day.
Saturday, August 29, 2026
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August 29, 2026 -Continental Divide Trail Run
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August 29, 2026 -Rock Hawk Trail Race
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August 29, 2026 -Boulder Sunset Triathlon
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August 29, 2026 -Boulder Sunset 5K/10K
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August 29, 2026 -Thirsty 13 Half Marahton
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August 29, 2026 -RexRun 5K for PAWSitivity
Continental Divide Trail Run
Distances: 50k (9 hour cutoff) and 16 mile (7 hour cutoff) and 5 mile (New!)
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. […]
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.
Thirsty 13 Half Marahton
It's a race. It's a Brewfest. It's the Thirsty 13 Half Marathon! Are you thirsty for gorgeous scenery? You won't find a course more beautiful than this one. With the majestic La Plata mountains in the background, you'll cruise through the lush pastures of Wildcat Canyon and past the pristine waters of Lake Nighthorse. This […]
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.
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