Event details subject to change. Please confirm all information via event website.
Arches Marathon
Started in 2004 as a fall companion to the popular Canyonlands Half Marathon, Arches Half Marathon has hosted many runners on the road course. In 2021, Arches became a trail event. The new course features beautiful red rock formations, views of the snow covered La Sal Mountains and the awe inspiring Behind the Rocks Wilderness […]
Colorado Springs Marathon
Join us for the 13th Annual Colorado Springs Marathon on Saturday, October 3, 2026! Whether you're a seasoned runner or taking on your first 5K, we have four exciting race options to choose from. Each course highlights the stunning beauty of Colorado Springs—winding past historic landmarks, through scenic parks, and finishing downtown at the Colorado […]
Above the Clouds Ultra
Experience the amazing Colorado fall colors, fast and flowing singletrack of Rampart Reservoir and the spectacular sweeping views of America’s Mountain, Pikes Peak, in the inaugural Above the Clouds Ultra!
West Elk Trail Marathon
The West Elk Challenge is a point-to-point trail marathon (with a 30K option) through Western Colorado’s North Fork Valley and West Elk Mountains at peak fall colors. But it’s also something bigger: 100% of proceeds fund scholarships for Nature Connection’s summer camps. This race is built around a simple idea: courage grows through challenge — especially […]
Castle Rock Trail Festival
Welcome to the Town of Castle Rock’s epic trail event. Come to challenge yourself on the vast ridgeline trail system and enjoy Castle Rock’s local trails. Trail run options range from the liveBIG 5K to the Ultra Marathon 50K. If you’ve run this trail system before, you know these are some beautiful and beguiling trails. […]
Taco Bell 50K
It has been described as Urban Legend. More mysterious and barking spiders than the Barkley Marathons. The International Taco Bell 50k boasts a higher DNF rate than the famed Leadville 100 Trail Race. As the tale is told, the race began with a hot tub, a stoic Russian, a short king from New York, and […]
Rim to Rim Royal Gorge Run
Get ready for a ROYALly GORGEous experience! Whether you’re tackling the 5K, the 8-mile trail run, or the half marathon trail run, this event offers something truly special. All three races feature the exhilarating opportunity to run across America’s highest suspension bridge, the iconic Royal Gorge Bridge, with breathtaking views of one of Colorado’s most […]
Sage Burner Trail Race
Nestled in the Rocky Mountains, about 2 hours east of Grand Junction and 3 hours west of Denver, lies a small running jewel called Gunnison, Colorado. Visit Gunnison, and you’ll be treated to some of the best outdoor recreation this planet has to offer.
Spooky Sprint Half Marathon
Join us for the annual Spooky Sprint 5k/10k & Half Marathon! A fun, Halloween-themed event that is perfect for the whole family.
The Ruff Run
Discover the ultimate Colorado adventure: a thrilling dog-and-runner race (2 miles) that celebrates your passion for running, the unbreakable bond with your pet, and the pure joy of playful challenges. Hosted on the stunning and scenic grounds of Boyd Lake State Park, this event pairs one enthusiastic runner with one eager canine companion for a […]
Outlast Denver
OUTLAST is a 6-hour trail endurance challenge where runners complete a 5K every hour, on the hour. Each lap must be finished within the hour to stay in the event. If you finish early, you rest until the next round. Miss a lap, and you’re out. Complete all six rounds, and you OUTLAST. This isn't […]
The Pretzel Run
Oktoberfest in Colorado!! Owned and managed by a Bavarian Race Director.... The Annual PRETZEL RUN will move 8 blocks down to Louisville Community Park for a LARGER BIER GARDEN, LIVE MUSIK and 4 Trail Races. Hlaf Marathon, 10k, 5k and Kids Mile. (Allows more room for the race) and the park will allow for a […]
Rut Run 5K
With the Fall Season, Estes Park shines in colors and wilderness experiences! Herds of Elk begin to roam the meadows and open fields; while sounds of bugling Bull Elk call out their territory. Join us as we acknowledge this unique season at the RUT RUN 5K as part of ‘ELK FEST’. Kick starting the weekend of […]
I Can 5K
You CAN 5k. This event is for EVERY ONE. EVERY BODY. You won't get lost. You won't get forgotten. You'll run a clearly marked 5k loop with multiple portojohns & aid stations along the way. And if you're up for a 10k you'll be running the same loop one more time! We're going to keep […]
Miles for Moms
Join us at the FloCrit campus and surrounding neighborhoods in southwest Denver for the Annual Miles for Moms Run/Walk/Roll! Lace up your running shoes for a fantastic 3-mile fundraiser run, where we celebrate the triumphs of the amazing teen mothers we support. A welcome and kick-off program will start off the event, followed by the […]
Crazy Horse Fast 5K
The Run Crazy Horse Marathon events begin in the shadow of the world's largest mountain carving, Crazy Horse Memorial, and finishes in the heart of the Black Hills... Hill City, South Dakota
Grace Race 5K
Help eRace World Hunger at Rainbow Trail Lutheran Camp’s Annual Grace Race! This annual 5k run/walk was started as part of RTLC’s 50th anniversary in 2007, to raise money for ELCA World Hunger. The event is held in collaboration with the Rocky Mountain Synod Hunger Network. Over the last 15 years, RTLC and the participants […]
Hot Chocolate 15K/10K/5K
Start and finish at Civic Center Park amongst Denver's biggest chocolate aficionados. All participants receive a technical running quarter zip with registration. Runners can also enjoy hot chocolate, chocolate fondue, and dipping snacks at the post-race party! It’s not just a race, it’s an experience. Register today!
Windsor Marathon
Welcome to the annual Windsor CO Race! This year's event will start and end at The Island at Pelican Lakes in Water Valley, with a great after party including beer, music and live entertainment! New to the series is a Full Marathon distance, as well as the Half Marathon and Heavy 10K.
Run Crazy Horse Marathon
The Run Crazy Horse Marathon events begin in the shadow of the world's largest mountain carving, Crazy Horse Memorial, and finishes in the heart of the Black Hills... Hill City, South Dakota
OTILLO Swimrun
Welcome to the world of ÖTILLÖ Swimrun! ÖTILLÖ Swimrun, the original swimrun race, embodies the spirit of adventure, endurance, and teamwork. Originating in Sweden, ÖTILLÖ translates to “island to island” in Swedish, reflecting the essence of the sport where participants traverse across a series of islands by swimming and running, often in challenging and picturesque […]
Michael J. Fox Foundation’s Run/Walk
We're excited to invite you to be a part of The Michael J. Fox Foundation’s Denver Run/Walk, a community event dedicated to raising awareness and funds for Parkinson's research. Lace up your sneakers and join us as we come together to make a difference in the lives of those living with Parkinson's disease. Event Highlights: […]
Rubey Rescue Run
Join us for a 5K uphill race on Buttermilk Mountain—with your furry friends, or without! Starting at the base near Buttermilk Mountain Lodge (formally known as Bumps) and climbing 1,700 feet to the Cliff House, this timed race ends with stunning views of the Maroon Bells. Prizes for top 3 female and male finishers. Also […]
Strides for Sierra 5K
Get your sweat on running or enjoy a leisurely stroll through the beautiful neighborhood surrounding Sierra Elementary! Starting at 10:00am the little ones can participate in a 1K fun run around the Sierra track. Afterwards stay and enjoy the Race Village with vendors, food, drinks and activities for the kids all while supporting the Sierra […]
Long View Marathon
Showcasing a unique city-to-city trail connection, The Long View Marathon and Half Marathon runs from Fort Collins to Loveland. Together, Gnar Runners and Sweetheart City Racing bring a unique collaboration to Colorado’s running scene in this one-of-a-kind race event.
CMRA Stone House Triple-Cross
The race will begin just west of Estes St across from the Stone House Park on Bear Creek in Lakewood. It will head west mostly on dirt trails through the creek side trees with a short piece on the Bear Creek bike path. Near the Fox Hollow golf course the route crosses Bear Creek 3 […]
Colorado Believe 5K
Know that you're part of something bigger. By raising awareness, we can help other families who may still be searching for answers. Any funds raised will go to Dup15q Alliance who provides family support and promotes awareness, research, and targeted treatments for Dup15q syndrome.
Manitou 5K
Come celebrate the beauty of Manitou Springs! Race starts and ends in Fields park. Run along the rolling creek, view the art along the Creekwalk, loop the beautiful parks full of murals, sculptures, disc golf, skateparks and more. The path is flat and accessible to all. Run/walk. Bring your family, bring your neighbor, bring your […]
Westy Half and 5K
Join the WESTY HALF and 5k this fall! The Hometown Race Series features half marathons and 5k distance events in outlying communities outside the Denver and Boulder metro areas. This is one of the few 5k events where FINISHER MEDALS are awarded to each participant.
Breakthrough T1D Walk
As the leading global type 1 diabetes (T1D) research and advocacy organization, Breakthrough T1D has played a crucial role in nearly every major T1D breakthrough in history. No organization does more to improve everyday life with T1D—from therapy development and access, to expanding research, advocacy, and community support. Breakthrough T1D Walk is the world’s largest […]
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