Denver's oldest half marathon runs along the Platte River Trail, covering parts of Littleton and Denver.

Welcome to the SPRING FLING Prairie Dog Half (part of the Prairie Dog Half series)! This spring-time event also features 10k & 5k distances!

Travel on foot through some of the most beautiful parts of Cherry Creek State Park, with a total combined elevation gain of only 253 feet spread out over 13.1 miles as the course follows the banks of Cherry Creek, Windmill Creek, and Cottonwood Creek on a mix of road, paved running trail, and wide dirt […]

Welcome to the 52nd running of the Horsetooth Half Marathon. Your race will take you on a scenic point-to-point journey from Hughes Stadium, the former home of the CSU Rams, to the finish line party at New Belgium Brewery. On the way you’ll tackle the challenging hills of Centennial Drive along the shorelines of the […]

Join us for the CU Boulder Diabetes Link Fundraising 5k Race this April 13th to support diabetes research and raise awareness!

We are pleased to offer 3 x Spring track meets, for middle distance and distance runners, that will be conducted similarly to the BMC (British Milers Club) meets. All meets will be held at Niwot High School (8989 Niwot Rd, Niwot, CO 80503). ADDITIONAL NOTES There are NO age restrictions for the 800m, 1500m and […]

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 […]

Rattler was created to feature one of Colorado Springs' best city parks, Palmer Park.  Runners will enjoy views of the city and Pikes Peak from the sandstone bluffs, while running all of the best trails the park has to offer! Even though the course does not have much vertical gain, it will test runners with […]

One of Colorado's favorite trails meets one of its most glorious parks at our 11th annual Beat the Heat! As courses wind southwest along Big Dry Creek Trail, the remarkable sight of Standley Lake with the Flatirons on the horizon will come into view. Its Endless Series sidekick in September is Fallfest. 5K, 10K, Half Marathon

The Great Western Trail is a wide unpaved trail located in rural Weld County in Northern Colorado. The trail connects to the Windsor Trail system on the northeast edge of the Town of Windsor, traveling north to the Town of Severance. From Severance, the trail curves east, and runs through open agricultural lands 7.5 miles […]

This race is a true handicap event in that it measures your fitness level based on your age, sex, height and weight! Following a victory at the Boston Marathon, Bill Rodgers said that his effort to run a 2:10 was not nearly as difficult as the effort of those who were “out there for 4 […]

This is the Most Eggcellent of excellent 5Ks - an 80s themed 5k!  Bring out your pastel, your shoulder pads, your blue eyeshadow, and that big hair!  We cannot wait to see your spirit!   We will start at McPhelemy Park, and then runners will travel west on Crossman Avenue (CR 350).  They will take a […]