Event details subject to change. Please confirm all information via event website.
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 […]
Niwot’s Challenge
Sedalia Post Office 4195 Douglas Ave, Sedalia, CO, United StatesNiwot’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 […]
Duck Waddle 5K
Lake Estes Marina 1770 Big Thompson Drive, Estes Park, CO, United StatesThe DUCK WADDLE 5K race begins at east side of Estes Park Parking Structure. Each runner and walker will follow the scenic Lake Estes Trail counterclockwise to the finish line (west of the Lake Front Parking area on north side of Lake Estes). The DUCK WADDLE 5K foot race welcomes all abilities and those wanting to have a ton of fun […]
Furry Scurry
Washington Park - Denver 701 S Franklin St, Denver, CO, United StatesThe 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 StatesMarathon, 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. For 2027 Boston Marathon qualifiers, races […]
Longmont Half and 5K
Longmont Rec Center 310 Quail Rd., Longmont, CO, United StatesLongmont's only Half Marathon - now offered in the cooler month of MAY! Join the Half Marathon or 5k distance! Walkers and Runners of all abilities welcome!
RMRR Central Park 5M/5K
Stapleton Central Park 8801 Martin Luther King Jr Blvd, Denver, CO, United StatesEveryone – slow, fast, or in-between – can win at RMRR Trophy Series races. With our handicap scoring system, we predict YOUR finish time based on recent running results, giving you a great goal to shoot for whatever your speed. Just show up an hour before the start and we’ll get you ready for your race. It’s an […]
Hayden Cog Run
Hayden Town Park 229 South 3rd Street, Hayden, CO, United StatesThe Hayden Cog Run is one of the longest consecutively run races of the Steamboat Springs Running Series and in the state of Colorado! This is a Routt County Classic held in the small town of Hayden Colorado 25 minutes west of Steamboat. The Cog Run is a challenging 8.4 mile out and back course […]
Quad Rock Trail Race
Lory State Park 708 Lodgepole Dr, Bellvue, CO, United StatesWelcome to the Quad Rock 50 and 25 mile trail races, an event put on by trail runners for trail runners. Taking place on the trails and hills west of Fort Collins in Lory State Park and Horsetooth Mountain Park, the Quad Rock 25/50 will take you on a tour of the Fort Collins skyline, […]
Valkyrie Women’s Trail Race
Cheyenne Mountain State Park 410 JL Ranch Heights, Colorado Springs, CO, United StatesValkyrie 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
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.