Estes Park Backyard Ultra

Estes Park High School 1600 Manford Ave, Estes Park, CO, United States

The Backyard Ultra with the views. ​ The Backyard Ultra is a form of Ultra race where runners must complete 4.167 miles in less than one hour, every hour, until only one runner remains to complete a lap. This runner is crowned the winner and only finisher, while all others will be marked as DNF. There is […]

Midsummers Night Run

Winter Park Resort 85 Parsenn Rd, Winter Park, CO, United States

Join us for an evening at Winter Park by participating in our Second Annual Midsummer Night's 10k!  This run will begin and end at the base of Winter Park Resort with an elevation gain of approximately 570 ft.  Enjoy a combination of gravel roads and trails on this run.

Timberview Trail Run

Lory State Park 708 Lodgepole Dr, Bellvue, CO, United States

Crisp morning air and a summer sunrise in Colorado. YES PLEASE! Join us on the foothills at Lory State Park for a fun & beautiful morning trail race. This run race features three distances (a 10 mile, a 5 mile and a 5K) that are great for just about any level athlete at any age. Run on […]

$20 – $50

Leadville Trail Marathon

Leadville 124 E. Sixth Street, Leadville, CO, United States

Run through the historic mining district’s challenging old mining roads and trails, and hit a high of 13,185 feet at Mosquito Pass during the Leadville Trail Marathon or Heavy Half Marathon. The views will leave you breathless, if you’re not already.

Pride 5K

Civic Center Park 101 14th Avenue, Denver, CO, United States

The Denver PRIDE 5K enables supporters of The Center on Colfax to raise funds in support of our mission. We provide critically important programs and services to Colorado’s LGBTQ community. 100% of each dollar raised by individual fundraisers goes directly to support our community members--including our youth center, health services, and social support groups. Join the race today!

Boulder Sunrise Triathlon

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

Join us in celebrating the start of summer in the triathlon capital of the country, Boulder, CO. An athlete favorite with its breath-taking sunrise swim, fast bike and smooth run course, all with the flatirons painted in the background. You’ll never want to race another venue again after this experience! The seasoned race crew led […]

Boulder Sunrise 5K/10K

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

The Boulder Sunrise 10k & 5k Run has a reputation of being one of the most scenic courses around. BBSC will provide runners with a supported course, including plenty of aid stations fully stocked and staffed with volunteers. Once you reach the finish line enjoy the post-race party with music, beer, food, and awards! This […]

PPRR Nielson Challenge

North Monument Valley Park 1794 Culebra Ave., Colorado Springs, CO, United States

Race 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 […]

Boulder Stroke & Stride V

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 […]

Chase the Moon Trail Race

Mountain Vista High School 10585 Mountain Vista Ridge, Highlands Ranch, CO, United States

Chase the Moon is a 12-hour team relay and solo ultramarathon, run overnight under the light of the full moon in the Highlands Ranch Backcountry trail system (we promise some of the best views of the metro and front range). Run as a solo ultrarunner, or get your fellow moon-chasing friends for a 3-person or […]

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.