Event details subject to change. Please confirm all information via event website.
Bear Chase Trail Race
The Bear Chase Race Endurance Festival is a 100K, 50 Mile, 50K, Half Marathon, Baby Bear 10K and 5K trail race at beautiful Bear Creek Lake Park, in Lakewood, CO. […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
HRCA Wildcat Mountain Trail Races
The Wildcat Mountain trail races take place starting at the Douglas County East/West trailhead at Rocky Heights Middle School and run along the E/W trail to the beautiful HRCA Backcountry […]
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 […]
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. […]
Grand Valley Backyard Ultra
This is a true last-man-standing event, and it will go until there is only one runner left, no matter how long it takes. Unlike all other competition race formats, this […]
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. […]
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 […]
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 […]
Emerald Mountain Trail Run
Howelsen Hill 845 Howelsen Pkwy, Steamboat Springs, CO, United StatesThis races offers two distances on Emerald Mountain, 12k (ends up being closer to 7.75 miles long) and a 4 mile run. This scenic course will begin at the base […]
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 & […]
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, […]
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, […]
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 […]
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, […]
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, […]
New Belgium Half Marathon
New Belgium Brewing Company 500 Linden Street, Fort Collins, CO, United StatesJoin us for the New Belgium Half Marathon and 5k on Sunday, October 4, 2026. The course starts and ends at this beautiful Fort Collins, Colorado brewery. The out-and-back course […]
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, […]
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” […]
RMRR 8M and 5K
Star K Ranch 16002 E Smith Road, Aurora, 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 […]
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 […]
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 […]
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