Showing 164 events within 100 km in the next 365 days. Page 2 of 9.
NO Race Day Registrations
Fun for all, from newcomers of any age racing for the first time to veteran competitors looking to test their fitness, all in a friendly, welcoming environment.
Held at the Historic Potts Field, home of the University of Colorado Track & Field Team, the facilities offer the full range of track and field events and is one of the only meets in Colorado that offer a chance to run the Steeplechase or throw the javelin.
If you've been wanting to try a track race and run in the footsteps of CU stars such as Jenny Simpson, Emma Coburn, Joe Klecker, Val Constien, Dathan Ritzenhein, Alan and Shayne Culpepper, and Kara and Adam Goucher, now is your chance!
Founded in 1979, the Eldorado Run for the Cure is the longest operating charitable footrace in the State of Colorado. All proceeds from the annual four-mile run benefit the Colorado Cancer Foundation's life saving work, from funding oncology research at the University of Colorado's (CU) Division of Medical Oncology to aiding patients at the CU Hospital in Aurora, CO.
Each year, the run has developed and grown, and in 2023 a new course was introduced, routing participants along the scenic South Boulder Creek, which winds through the high cliff walls of historic Eldorado Canyon.
Founded in 2011, over 10,000 B Strong Riders have raised over $5 million to fund the B Strong Center for Integrative Care at Boulder Community Health and support other local cancer charities.
Event T-Shirt & Jersey:
[B Strong 2026 T Shirt.jpg] [b48c1cff-0f1d-4a09-b7d4-f1d920d563a8.jpg]
August may be hot...but still a great time to run, and we hope you'll come join the runners of RMRR. We'll run our August 5k on the Highline Canal around DeKoevend Park. As always, everyone is welcome.
For August, we use a mass start rather than our standard handicap start system.
Race Day Details
Date: Friday August 4th
Time: 6:30 pm start. Show up 30 minutes early to walk from your car, get your registration info, and warm up.
Distance: 5k.
Course: Race runs on the crusher/fine dirt Highline Canal around DeKoevend Park.
Course on Strava: https://www.strava.com/segments/22931643
Location: DeKoevend Park in Centennial. We run from the pavilion behind the Goodson Recreation Center.
Google Parking Link: Goodson Rec Center Parking. Park towards the far W end of the lot.
Stick around after for our potluck BBQ. RMRR provides the grillables and non-alcoholic drinks. We ask everyone to bring a salad, side dish, or dessert to share.
As the summer mornings start to cool, join us for a fantastic end-of-season celebration at our 14th annual Runapalooza! From our new venue at Colorado Tap House, you'll have the chance to tackle relatively gentle 5K and 10K courses that go along the acclaimed Ralston Creek Trail, taking you through shady, creekside beaty along Arvada's picturesque open spaces and charming golf course communities. Or our challenging half marathon course that combines the beauty of the Ralston Creek Trail with the challenging Blunn Reservoir loop with its gorgeous Denver and Front Range views. This event, paired with its Endless Series' counterpart Mardi Crawl, offers a can't-miss opportunity to experience the best of what Colorado has to offer!
Join us for the annual Summer Sizzler 5k/10k/15k! A fun summer event that is perfect for the whole family.
The fun includes -
Great Swag - designer shirt & custom medal
Chip-timing with live results and awards
Free photos
Delicious Treats waiting at the finish line
FREE Shaved Ice!
Plenty of fun!
Grab your friends and family, you are not going to want to miss this one!
Can't make the race? No problem! We offer a virtual race option where you can run anywhere, at any time, and still earn the fun swag!
*Youth-based pricing for the 5k/10k, 12 & Under are only $17!
5k/10k/15K registration includes a custom bib, designer shirt, and a custom finisher medal!
1 Mile registration is untimed and includes a custom bib, designer shirt, and a custom finisher medal!
The kid's dash is a fun, untimed dash for our kiddos ages 10 and under. Registration includes a mini bib, youth-sized shirt, and a specifically crafted medal for our kids' dash event! (If your child wants to run the kid's dash, and doesn't want the SWAG, they are welcome to run with us on race day for free!)
*Register by midnight on Thursday, two Thursdays before race day, to guarantee your shirt!
🏁🏅Create a team, or join an existing team during registration. Once 4 people have registered on that team, all team members will be refunded $5, once ten people register another $5 will be refunded for a total of $10!
Come join us for a race around the entirety of beautiful Lake McIntosh! This 3.5 mile race is a half paved/half dirt course surrounded by wonderful mountain views, vast farmlands, and beautiful aquatic wildlife! Gather at Dawson Neighborhood park near the pirate ship playground where you will find an assortment of vendors, music, games, and fun! All are welcome to participate in this awesome event! Doggos are encouraged to participate!
! NEW ADDITION ! We are so excited to announce the Kids Dash! Please bring your kiddos to enjoy a mad dash to the finish line near the Pirate Ship Playground at Dawson Park!
Run. Support. Celebrate.
Join us for the 7th Annual Arapahoe Warrior 5K and support the Arapahoe Warrior Cross Country Team!
With $10 from every registration going directly to the Arapahoe Cross Country Booster Club, your participation makes a real difference for these hardworking athletes.
Enjoy a scenic run through the beautiful residential streets of Centennial on a measured, clearly marked course—perfect for runners, joggers, and walkers alike.
Post-Race Pancake Breakfast
After crossing the finish line, celebrate with a delicious pancake breakfast by Flippin’ Flap Jacks—complete with sausage and refreshing orange juice—free for all registered participants.
Custom T-Shirts
Add a race T-shirt to your registration for just $14.
Order by July 14th to guarantee yours.
Shirts are fitted—size up if you prefer a looser fit.
Finisher Medal & Awards:
Top 3 in each age group earns a custom 3.5” die-cast medal with a unique lanyard!
Top finishers will also be recognized:
Overall Winners
🏆 Male Overall Winner
🏆 Female Overall Winner
Age Group Awards – Top 3 in Each
10 & Under – Boys/Girls
11–12 – Boys/Girls
13–14 – Boys/Girls
15–19 – Boys/Girls
20–29 – Male/Female
30–39 – Male/Female
40–49 – Male/Female
50–59 – Male/Female
60–69 – Male/Female
70+ – Male/Female
That’s 62 total custom medals up for grabs!
Race Day Details
📅 Race Day: Saturday, August 8th
⏰ Start Time: 8:00 AM
📍 Location: Arapahoe High School – 2201 E Dry Creek Rd, Centennial, CO 80122
Packet Pickup & Registration
Friday, August 7th – Pre-Packet Pickup: 9:00 AM–11:00 AM at Arapahoe High School
Race Day Registration – Opens at 7:00 AM ($40)
Parking
Available at the high school and nearby neighborhoods.
Course Info
🏃 Course Type: Out-and-back
📈 Elevation Gain: 109 ft
📉 Elevation Loss: 89 ft
⬇️ Min Elevation: 5,575 ft
⬆️ Max Elevation: 5,665 ft
The Splash Mash Dash Kids Triathlon is perfect for kiddos looking for a way to "TRI" the sport of triathlon or tune up their skills for a larger race. The race will offer kids a safe and fun environment for racing.
To encourage participation and enjoyment for all, The Splash Mash Dash Kids Triathlon is a non-timed event. However, we do have awesome finisher medals that look just like the medals they've seen parents collect over the years! We encourage every child to do their best and practice racing in a supportive environment. We encourage parents to manually time their child if they are interested in a time for their race.
Eat. Run. Adopt.
Join us for Berthoud’s first-ever community-driven 10k!
In partnership with Berthoud Pet Supply, this isn’t just a race—it’s a moving feast with a mission. A portion of race registration proceeds will go to Scroungy Dogs and Pretty Pups Rescue This community race and expo is designed to support Scroungy Dogs and Pretty Pups Rescue, a local 501(c)(3) non-profit dedicated to rescuing and rehoming dogs and cats throughout Northern Colorado.
Inspired by the spirit of the famous Taco Bell 50k, we are hitting the pavement to celebrate the heart of our town: our local cuisine, and small businesses. Runners will run around town stopping at set up food aid stations with a sample of the local restaurants food. They will wear a wristband that will be hole punched to show they completed eating their samples. They can collect all samples and eat them at the finish but need to hole bunch their wristband to confirm they made the stops.
Prizes for the overall winner are BOLDERBoulder 2027 entrance + cash prize. Runners up in men, women, kids, seniors get a gift basket with local items from local businesses.
THE 2026 BRECK EPIC
August 9-14, 2026
Back to the beginning. When mountain biking was a about big rides with friends. About lending a hand when a rider went down. About how a shared experience on a challenging backcountry course disproportionately enriched all involved.
INCREDIBLE COURSES
The Breck Epic is composed of 6 BIG backcountry loops (3 loops for the 3-day Epic-curious events), each between 35 and 50 miles long. The event is unique in that it employs a cloverleaf format; each loop starting and finishing within a mile from downtown Breckenridge. The race utilizes the magnificently sprawling and interconnected network of trails that span the width and breadth of Summit and Park Counties.
When mapping out the courses we asked ourselves; “What big rides would we want to tackle if we had most of the day to slaughter and 6 of our best friends along for the ride?” The answer lies before you. The six stages that compose the Epic are a well-rounded rider’s dream. Long middle-ring climbs, endless big-ring mashing descents.
THE LONG HAUL
The 2026 version of the Epic marks our 18th edition. That's a lonnnnng time! "Time," some would.say, "To spice things up!" We think you'll like what we have on deck. The race is rad. The courses are beyond fun. The vibe? Mid-90’s mayhem. And Breck? It's amazing. Great people, amazing food and unbelievable weather.
In an average year, Epic will host riders from 25 different countries and 40 states. Why? We think because events like ours are just rare. It's a unique combination of mayhem and organization, with a huge emphasis on camaraderie and community.
BIGGER ISN'T BETTER - 400 RIDER LIMIT
We'll also be limiting the field in 2026. This is a statement about how we feel about the quality of the race experience. We simply believe that it's more fun when there are fewer people out there. Bigger isn't better. BETTER is better. We think you'll have a better time without your snout poking up some other rider's tailpipe all day. Not that there's anything wrong with that. But as they say, unless you're the lead dog, that view is always the same.
We feel that our course can handle more, but the question is, "Should it?" Our personal answer is no. Our commitment to our riders and to our trail network and community is to keep our numbers down. Because it's a better experience for our riders and because it lessens the impact on our trail system.
So yeah. Space is limited. That's by design.
If a weeklong tour of the world's greatest high alpine trail network sounds like your cup of tea, come join us. We’ve got great people in a great town with courses that you’re gonna need to ride to believe. What else do you really need?
MikeMac
Event details and schedule
Join us August 5, 12, 19 & 26 for a fun series of shorter midweek trail races.
Our goal is to offer a fun, low-key series of races designed to give newer trail runners an opportunity to dip their toes into the trail racing waters, and to offer more experienced trail racers a chance to sharpen their speed on shorter, quicker courses. All races will start at 6:00pm, ranging in distance from 5k to 12k. Results will be tabulated according to chip times, with series points awarded for each race. Top series finishers will earn unique awards.
We'll have a wide selection of vintage Gnar race shirts, and all registrants are welcome to their pick to call their own.
After each race, we will be providing pizza with support from the Fort Collins Running Club and beverages with support from New Belgium Brewing.
Race dates and distance are as follows:
August 5: Flat and Fast Eltuck Valley 5k (250′ elevation gain)
August 12: Into the Hills Eltuck 5k (700′ elevation gain)
August 19: Into the Hills Eltuck 10k (1,700′ elevation gain)
August 26: Flat and Fast Eltuck Valley 12k (500′ elevation gain)
Start: Lory State Park, Eltuck Picnic Area, Fort Collins, Colorado
Distance: 5k - 12k
Dates: August 2026
Time: 6:00pm
Cost:
Thru 6/30: $25 each race or $80 for the series
7/1 & After: $30 each race or $100 for the series
Special pricing of $10/race for Ages 17 & Under. Price change will be automatically applied based on registrant's Date of Birth before final checkout on RunSignup.
All race participants are welcome to a free vintage shirt from previous Gnar races (your choice and as available). Awards will be given out at the end of the series to top points scorers.
We acknowledge and respect those who experience their gender identity in ways outside of the traditional male/female dichotomy, and are trying our best to provide non-binary opportunities in both the registration and results to reflect that. For the purposes of awards, non-binary runners will be eligible in their birth gender pool.
Race dates and distance are as follows. Click the race link to view the course map
Trail Sisters Approved
Transfer Credit & Distance Change Policy
If you are not able to race, we can offer a 75% race transfer credit that can be applied to any future Gnar Runners race (valid for 12 months). We can also directly transfer your entry to another race in the series for the same year, assuming the new race is not sold out. Transfers/Credits can be requested any time up until 72hrs before the start of each race in the series. To request a transfer credit please Contact Us.
Cancellation Policy
With the exception of waitlist transfers, entries are non-refundable and non-transferable. In the event the race is cancelled due to extreme weather, fire, disease or for some other unforeseeable event, we cannot offer refunds or credits.
Rules
Purposeful littering is prohibited and will result in an immediate disqualification.
Stay on the trail. No bushwhacking or short cutting. In case of wet trail conditions, please run through any muddy sections to avoid widening the trail. Yield to pedestrian and horses. Mountain bikers should yield to runners, but please use common sense in all circumstances.
If coming up on a slower runner or regular park user while on trail, please give an early verbal notice that you are approaching and wait for the hiker/runner to step off to the side before passing.
No mechanical aid (poles, traction devices, etc.) unless approved by race staff prior to the race for a specific reason.
Dogs are not allowed on the course with runners.
If you do not have an annual Colorado State Parks Pass or a pass with your vehicle registration, you will need to purchase a day pass ($10) when you enter the park.
Parking will be at the Eltuck Picnic Area until filled, after which we will direct cars to the nearby Spur Road. For those parking on the Spur Road, it will be a short walk to the start.
Bibs will be available for pick up at the race start from 5:00pm. Chips will be pre-attached to your bib. If you are running multiple races in the series, please keep your bib to reuse in your next race(s).
Aid, Etc
These are no frills, basic races. There is no on-course aid.
There are two permanent toilets at the start/finish of each race. Additionally, the Valley 5K goes past park restrooms at the 0.25 and 1.5mi marks; the Hilly 5K & 10K go past a park restroom at the 0.25mi mark, and the Valley 12K goes past park restrooms at 0.25, 3.8, 6.1 & 6.3mi marks.
The Summit Mountain Challenge is a Mountain bike race series located in Summit County, Colorado. Take advantage of the various single track trails around Summit County, while competing against others. We have courses and age categories depepdning on your skill level. Register for the entire series to receive 30%. Following each race, participants over the age of 21 will receive a beer. Do not miss out on this outdoor party that is disguised as a bike race!
Event details and schedule
Day-of registration will be available for $35 beginning at 4:00pm on race day at each trail head, along with bib pickup. We accept Cash, Checks and Credit Cards.
The category start times listed on our website are subject to change:
This is it: the race of all races. One hundred miles across the high-altitude, extreme terrain of the Colorado Rockies, this event was created for only the most determined athletes. Starting at 10,152 feet and climbing to 12,424 feet, you’ll be challenged to catch your breath—while the views try to take it away.
The Chris Klug Foundation (CKF) has been a charity partner with Lifetime since 2012, raising over $250,000+ for CKF's programs. CKF's Leadville Trail 100 charity team helps to educate others on the facts of organ, eye & tissue donation, while raising awareness for the those awaiting a lifesaving transplant nationwide.
Miles for Migraine will host its 6th annual 2-mile Walk, 5K Run and Relax Denver Event at Great Lawn Park. This event is a fundraiser for Migraine & Headache Awareness, Treatment & Research. Dress up in your best purple flair for a chance at a fun prize!
All funds raised will benefit the University of Colorado Headache Center and Children's Colorado Headache Center to support local migraine research and fellowship training programs.
Registration: https://den.milesformigraine.org
Registration has moved to den.milesformigraine.org
Miles for Migraine will host its 7th annual 2-mile Walk, 5K Run and Relax Colorado event on Saturday August 15th at Great Lawn Park in Denver. This event is a fundraiser for Migraine & Headache Awareness, Treatment & Research. It's more than a walk/run - come connect with your local migraine & headache community, listen to our speakers & visit sponsors in the festival area.
The 5K run is professionally timed. The Walk and the Relax events are free, but donations are encouraged. All walk and run finishers receive a finisher medal.
Dress up in your best purple flair for a chance at a fun prize!
Funds raised will benefit Miles for Migraine free programs & services as well as the University of Colorado Headache Center and Children's Colorado Headache Center to support local migraine research and fellowship training programs.