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 Race Series. This spring-time event also features 10k & 5k distances!

This event is for all ages and abilities, whether you're in it to win or out for a fun Sunday morning walk. Come out and take a step to help kids in Grand Junction by participating in the 2.5K, 5K, or 10k distance. *The really littles, 4 & under, can participate in the free Hatchling […]

The Donut Dash 5K is Denver’s race that ends with doughnuts. Runners and walkers can take advantage of a flat and fast course, and then enjoy fresh doughnuts at the finish. Our mission is to bring people together to have a fun, fit morning.

Everyone – 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 […]

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

Are you ready for the COOLEST event of the season! Whether you're a daring plunger, a speedy 5K runner/walker, or a thrill-seeker ready to do BOTH, the Polar Plunge & 5K promises non-stop excitement and heart-pumping fun - all while supporting Special Olympics Colorado. Take the plunge into a chilly pool, dash through the 5K, or double […]

Question:  Is it supposed to be DO NOT STOP, or DONUT STOP?  Answer:  YES! Like Running or Walking?  Love Donuts?  This race is for you! Join us for the annual Donot Stop 5k/10k and half marathon! A donut-themed event that is perfect for the whole family. The fun includes great swag (designer shirt, custom medal), […]

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 […]

FORMAT: 3 mile run - 12.5 mile bike - 3 mile run WHERE: Fort Lewis College. Most of the bike and run courses utilize FLC roads/grounds and Rim Drive. See Course maps.

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 […]