Event details subject to change. Please confirm all information via event website.
Big Waves 5K
Hi Friends of Big Waves! We are looking forward to having everyone back for our family 5k this year! We are going to do a superhero theme, so come dressed as your favorite good-doer! We will be back at Lifetime Fitness in Westminster (off 144th an I-25). Please reach out if you have any questions […]
CSU Homecoming 5K
The Homecoming Race will take place on the Oval for our traditional course. All ages and abilities are welcome. Proceeds from the Homecoming Race benefit the ongoing research efforts and outreach engagements offered by the Department of Health and Exercise Science. HES is committed to a life-altering education for every one of our 1,400 undergraduate […]
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.
Cart to Cart Trail Run
10 or 19 mile trail runs at the height of fall colors in Crested Butte. Fun prizes to winners and random participants. https://www.cbmountainrunners.org
Mines Homecoming 5K
Campus is gearing up for a Helluva Homecoming and we can’t wait to welcome you back! Check out the Homecoming schedule to see everything happening throughout the weekend.
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 […]
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 one isn’t about speed. It’s about grit, determination, and pure will to finish another lap. When you’ve had enough and don’t think you can finish […]
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 […]
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 of Howelsen Hill and tour Emerald Mountain through aspen lined single track. Hikers are welcomed in the 12k. This race is a fundraiser for Northwest […]
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 […]
Miner Gold Rush 5K
Prospect Ridge Academy is thrilled to present our Annual Miner Gold Rush and Fall Festival! All proceeds will benefit Prospect Ridge Academy, a public charter school providing a rigorous, quality K-12 education with an intensified math and science focus. Help support the school while having fun in this exciting community event!
Mustang Music 5K
5K DETAILS: The 5K features a chip-timed race designed to show the beauty of the neighborhoods by Kinard Middle School. Enjoy the music along the course provided by the Kinard and Fossil Ridge bands. REVERSE PARADE/FUN RUN DETAILS: Perfect for young children and non-runners, the Reverse Parade is a Fun Run in which participants will […]
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.
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 along the Poudre Trail will offer scenic views while running along the Poudre River. There is also a 5k fun run option. Start Times: The […]
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 […]
Tortoise & Hare 4K
Rolland Moore Park 2201 S Shields St, Fort Collins, CO, United StatesThe Tortoise & Hare (T&H) is a low-key “handicap” series of seven races that are run monthly from October to April, typically on the first or second Sunday of the month. Computer-predicted times allow runners of all levels to compete equally. Runners start at staggered intervals with faster runners (Hares) trying to catch slower runners […]
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 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 […]
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 […]
Splashland Triathlon
Catch a glimpse of the Great Sand Dunes National Park with six 14’nrs in the background Mt. Blanca, Colorado’s 3rd highest peak overlooks the valley floor.
PPRR Fall Series I
Bear Creek Regional Park 245 Bear Creek Road, Colorado Springs, CO, United StatesThe Fall Series consists of four trail races in four different city/county parks. The trails range from well-maintained to rocky with tree roots. Each event is a unique challenge at a different distance, getting longer as the series progresses. Fall Series I - 3.8 MileFall Series II - 4 MileFall Series III - 5.5 MileFall […]
Liberty Energy 5K
Please join Liberty for our 5K run and walk, benefitting the Bettering Human Lives Foundation. This family-friendly event will include live music, a beer garden, face painting, food trucks, and more! Every dollar we raise will support the foundation's mission of expanding access to clean-burning cooking fuels in sub-Saharan Africa by funding African innovators and […]
Please click here to submit your event for FREE to our online calendar.
We do not allow events without physical locations (IE – virtual runs, runs with locations TBD, etc…).
Please allow 48 hours after submission for an event to appear on the calendar. If you have already listed your event and would like us to update it, please contact us.