Event details subject to change. Please confirm all information via event website.
Ugly Sweater Fun Run
Grab your best and ugliest holiday sweater and join the Vail Recreation District for a fun-filled morning run through Vail Village on December 11th.
Jingle Bell Run
Get ready for this year’s Jingle Bell Run, the original festive race for charity brought to you by the Arthritis Foundation. Wear your favorite holiday gear, and let's jingle all the way toward a cure! Whether you're running, walking, or strolling, bring your friends, family, and coworkers along for the ride. Together, we're spreading joy […]
Candy Cane Chase
Now in it's 5th Year...we will have 2 now courses at the Creek Oath and Westminster Park is finished! We get the same families coming back year after year, Celebrating the upcoming Holiday Season. Collecting the different Mugs each year.... This years mugs will be made of Glass. and the Finisher Medal TURNS INTO A […]
Sweaty Sweater 5K
Front Range Community College - Fort Collins 4616 S Shields, Fort Collins, CO, United States5k Run/Walk – 9:00 am Kid’s 1-Mile – 10:00 am Calling all Ugly Sweaters… We want to see your most hideous, outrageous, bulky and unforgettable UGLY sweater running the Sweaty Sweater Race. This is an event for everyone, whether you are walking with friends, running for an award or even prancing towards the finish line […]
Santa’s Dash for Ca$h
Join 3W Races on December 18th at Sloan's Lake Park. Collect your prize envelope at the finish line for gift cards from local businesses and maybe even CA$H!
Resolution Run 5K
Run out the old year, and welcome the new! Now in its 42nd year, the Resolution Run is a family-friendly, neighborhood streets 5K starting & finishing at the Edora Pool Ice Center. Kids, strollers, dogs & walkers welcome! Finish in under 20:26 to earn a special prize! The race is held after sunset – we’ll […]
Rescue Run
Welcome back to Norris-Penrose Events Center / Bear Creek Park! Back in the beginning... The Rescue Run Start/Finish was at Norris-Penrose Events Center - After many wonderful years at Palmer Park we are returning back to our roots! But rather than run on the streets, as we did then, we will be running on the […]
Resolute Runner 5K
The Resolute Runner 5K is the KICK OFF PARTY OF THE YEAR! It's time to be RESOLUTE, to retroactively earn your pumpkin pie and chocolate truffles, and to start the new year on the right foot, literally! The course starts at Johnny Roberts Memorial Park in Arvada, CO, and winds through the beautiful Ralston Creek […]
Hot Chocolate 5K
Warm up your taste buds because you’re invited to the very first Hot Chocolate 5k Run! Come run your personal record and enjoy some post-race treats. This race is the perfect way to end 2025! Cross the finish line to a sweet reward of rich and delicious hot chocolate.
Ralston Creek Half Marathon
Move by Morelli 6542 Fig Street, Arvada, CO, United StatesThe Ralston Creek races feature a fun winter half-marathon and 5K run conveniently located on the west side of the Denver Metro Area in Arvada, Colorado. The courses covers a scenic mix of road and bike path over rolling terrain, and an optional early start time for half-marathon runners who expect to take more than […]
Chilly Cheeks Winter Duathlon
Cherry Creek State Park 4201 S Parker Rd, Aurora, CO, United StatesThe Chilly Cheeks Duathlon Series is now a stand-alone event held in late February. The 63rd Chilly Cheeks Duathlon will be held in the traditional format of Run-Bike-Run. Both runs will be 2.5 miles in length and the bike course will be an 11 mile paved road route. As always, we will provide a marked […]
That DAM Run Half Marathon
Get ready for the Best Dam Run you'll ever do! From your first step to your finish-line celebration, this race is packed with epic views, big accomplishments, and just the right amount of dam fun. Choose from a Half Marathon, 10K, or 5K as you race along Cherry Creek Dam with panoramic views of Denver and the […]
Runnin’ of the Green Lucky 7K
Feeling the luck o' the Irish? Lace-up and chase the rainbow in Denver’s favorite Irish-themed run! Join us at Washington Park for some shenanigans! Runnin' of the Green (ROTG) is a family-friendly 7K and 2 Mile race/walk celebrating Irish traditions, Saint Patrick’s Day, and Spring! The event promises to be a day filled with Irish fun, live music, awards, […]
Far Out 3/4 Marathon
Chatfield State Park 11500 N. Roxborough Park Rd, Littleton, CO, United StatesWe host one race per month from November to March. All races are at Chatfield State Park and start at 9:00 am on Saturday mornings. Check-in starts at 8:15 am.
Three Creeks Half Marathon
Racing Underground brings you an amazing half marathon this spring! The Three Creeks Half Marathon features a half marathon course that is flat, fast and scenic! Travel on foot through some of the most beautiful parts of Cherry Creek State Park, with a total combined elevation gain of only 291 feet spread out over 13.1 […]
Donut Dash
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.
Mountain Ridge Trail Race
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% […]
Platte River Half Marathon
Denver's oldest half marathon runs along the Platte River Trail, covering parts of Littleton and Denver.
Rattler Trail Race
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 […]
Royal Gorge Groove Trail Runs
Prepare for some fun in Cañon City! Enjoy scenic views along the rim of the Royal Gorge, 900 feet above the Arkansas River. All races will start/finish at the Royal Gorge Ranch & Resort. Distances include a 50K, 30K, 20K, 13K, 5K and Kids Run. Make a weekend out of it with river rafting and […]
Greenland Trail Race
The Greenland Trail Race offers four outstanding distances in southern Douglas County. Run the 4 Miler, the 8 Miler, the 25K, or tackle the 50K ultramarathon, Colorado’s fastest 50K! With Pikes Peak as your backdrop, you’ll cruise over a soft dirt trail on your way to a new personal best. With chip timing, an innovative technical running shirt in men’s and women’s sizing, food and beer at the finish, this race will make you want to come back for more!
Colorado Marathon
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. For 2027 Boston Marathon qualifiers, races […]
Wine Run 5K
Like Running or Walking? Love Wine? This race is for you! Join us on Saturday, May 8, 2027 at 9:30am and 11:00am (you will pick your start time during registration) for an exciting annual event that features the amazing scenery and landscape of Colterris Winery! With over 75 acres of vineyards, Colterris is Colorado’s largest […]
Ram Party Trail Runs
With plenty of race options for everybody centered around the beautiful Rampart Reservoir in Woodland Park, Colorado, you're sure to have a good time while you take in the epic views of Pikes Peak and the front range. 55 Mile | 60K | 50K | 24K | 15K
North Fork Trail Race
The North Fork 50 Mile/50K is 100% trails, mainly single track and some double track, starting and finishing along lovely Buffalo Creek, in the mountains about 50 miles southwest of Denver. This is a pure ultra, a very special and unique race, deliberately kept small so each runner gets personal attention. There are no non-ultra […]
Barr Lake Trail Race
The Barr Lake Trail Race returns to Brighton, CO, offering beautiful lake views and a prime opportunity for new PRs. Now in its sixth year, this event features our flattest and fastest course, with less than 100 feet of elevation gain per loop. Starting and finishing at the Nature Center, runners will enjoy a scenic […]
Colorado Triathlon
The Colorado Triathlon is where Colorado comes to race! The Colorado Triathlon - sprint & olympic distances, duathlon & aquabike options . To make this the "can't miss" event of the season, we'll also have athlete hoodie sweat shirts, and the best swag bag of the season. For us this race is about one person, […]
Lory Off-Road Triathlon
XTERRA Lory Triathlon is the perfect kick-off to the year for the seasoned off-road triathlete, or a great opportunity for the road triathlete wanting to try out a mountain bike triathlon for the first time. The XTERRA Lory Triathlon features a 1/2 mile swim in the clear waters of Horsetooth Reservoir (Eltuk Bay), it's one […]
Ring the Springs Trail Races
Get ready for an unforgettable adventure at Ring the Springs trail running races in the stunning Colorado Springs, Colorado! This thrilling event showcases the area's incredible natural beauty, with a course that weaves through majestic mountains, scenic city parks, and iconic landmarks. The route is designed to challenge and inspire, featuring exhilarating climbs and rewarding […]
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 […]
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