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 […]

Niwot’s Challenge

Sedalia Post Office 4195 Douglas Ave, Sedalia, CO, United States

Niwot’s Challenge is a very difficult, grass-roots, ultramarathon in Colorado’s Front Range. It is modeled after the arduous Barkley Marathons in Tennessee, and the historic More and More Difficult 50K in New Hampshire. Much of the information for this event is kept secret with an exception for those who are accepted for entry. This is […]

Furry Scurry

Washington Park - Denver 701 S Franklin St, Denver, CO, United States

The Furry Scurry is an annual, fun-filled festival and two-mile dog walk at Denver’s Washington Park to benefit the animals at the Dumb Friends League.  No matter where you scurry, every step you take and dollar you raise will make a lasting difference for the animals in our care. 

Colorado Marathon

Washington Park - Fort Collins 301 Maple St, Fort Collins, CO, United States

Marathon, Half Marathon, 10k, 5k and 3-Person Marathon Relay.  Marathon, Marathon Relay and Half Marathon runners get to run down the scenic, downhill Poudre Canyon to the finish in Old Town, Fort Collins, where we have live music and a big post-race party featuring beer from Odell Brewing Company.

Moose Mudder

Altitude Elementary School 27300 East Southshore Drive, Aurora, CO, United States

Please join us for the Annual Moose Mudder! This is a community event that will consist of an untimed 1k fun walk/run and a timed 5k followed by an optional muddy obstacle course. Get your best time, run for fun, walk with a group, form a stroller brigade, or line the streets to cheer everyone […]

Mountain Ridge Trail Race

Mountain Ridge Middle School 10590 Mountain Vista Ridge, Highlands Ranch, CO, United States

Mountain Ridge takes place near Highlands Ranch primarily on the Douglas County East-West Regional Trail. This gently rolling course will keep the Heart Rate pumping while offering some of the best views in the front range. The Mountain Ridge Trail Race will once again start and finish from Mountain Ridge Middle School, and offer 100% […]

Valkyrie Women’s Trail Race

Cheyenne Mountain State Park 410 JL Ranch Heights, Colorado Springs, CO, United States

Valkyrie Trail Race was created as a women only trail/ultra event,  featuring Colorado Spring’s, Cheyenne Mountain State Park.  The race offers amazing views of the city and a diverse eco-system. We have several different distances available, so everyone in your running group can participate! 50K/Marathon/30K/Half Marathon/8 Mile/4 Mile

Colorado Women’s Classic

Westminster Promenade 10600 Westminster Blvd, Westminster, CO, United States

We are excited to return to Westminster for the 2024 Colorado Women's Classic! While focused on women, all genders are WELCOME at this event! 10M, 10K and 5K races. We will run this event rain or shine! :) This is THE race for ALL. THE. GOODIES. The Colorado Women's Classic is about the POSITIVE parts […]

Endure Trail Runs

Mueller State Park 21045 State Highway 67, Divide, CO, United States

The Endure 12-Hour is a one-of-a-kind challenging 12-Hour timed event, designed by YOU… and tiny colorful balls. Each runner will pull colored balls from a bucket, which determines the loop they’ll next run. This continues for up to 12-hours in time, and the runner’s result is the number of miles they ran within the allotted time. […]

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.