Found 39 races near Boulder

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SEP
26

Estes Park, CO
• 20.6 miles
$90 -$265
​Join us for the Estes Epic on September 26-27, 2026 —a premier event featuring a 50k Bike Race, 50k Run, and Heavy Half Marathon. After a six-year hiatus, this challenging race returns, offering...
Half Marathon 50K
39
SEP
27

Boulder, CO
• 7.0 miles
$40 -$500
This is a virtual race open to supporters across the country who want to take action for children and families. Participants can run, walk, or move in their own community while supporting a...
5K 10K Half Marathon
17
OCT
10

Fort Collins, CO
• 37.1 miles
$35 -$120
Join us on a journey from Fort Collins to Loveland. The marathon begins at Edora Park in Fort Collins and ends at Fairgrounds Park in Loveland. The half-marathon starts at Fossil Creek Park and...
5K Half Marathon Marathon
54
OCT
10

Breckenridge, CO
• 55.0 miles
$25 -$150
Join us for an unforgettable two-day running experience in the heart of Breckenridge!Our Breckenridge RunFest kicks off Saturday with a 5K and 10K along Main Street, followed by the Half Marathon...
5K 10K Half Marathon Marathon
21
OCT
11

Westminster, CO
• 21.1 miles
$45 -$85
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.  Whatever...
5K Half Marathon
87
OCT
17

Fort Collins, CO
• 33.3 miles
$100 -$130
Welcome to the Blue Sky Trail Marathon & Half, Fort Collins's original and only trail marathon. Taking place on the trails between Horsetooth Mountain Park and the Devil's Backbone Open Space,...
Half Marathon Marathon
3
OCT
18

Denver, CO
• 31.7 miles
10K Half Marathon
32
OCT
31

Centennial, CO
• 46.2 miles
$30 -$45
Smooth vibes. Sweet energy. Bold moves. 🥜🍓 PB&J Fuel Run is all about a combo that just works. Mix your pace, spread the fun, and stick with it all the way to the finish. No stress, no...
1m 5K 10K Half Marathon
13
NOV
7

Littleton, CO
• 50.6 miles
$17 -$85
Join us for the annual Turkey Trails 5k/10k/Half Marathon!  A fun, Thanksgiving-themed event that is perfect for the whole family. The fun includes - Great Swag - designer shirt & custom medal...
1m 5K 10K Half Marathon
51
NOV
7

Lone Tree, CO
• 46.3 miles
$65 -$95
The 18th Annual Backcountry Wilderness Half Marathon returns to Highlands Ranch on Saturday, November 7, 2026, at 9:00 a.m. This 13.1-mile race winds through the Douglas County East/West Trail...
Half Marathon
1
NOV
14

Centennial, CO
• 46.2 miles
$30 -$45
Celebrate this Veterans Day with our annual Freedom Run! 🏃‍♂️💨 Kick off your weekend with purpose and pride by joining our 5K, 10K, or Half-Marathon. Whether you're running for a personal best or...
1m 5K 10K Half Marathon
6
NOV
28

Centennial, CO
• 46.2 miles
$30 -$45
Get Ready to Wobble Before You Gobble! 🦃 Join us for the annual Thanksgiving Gobble Trot! Before you dive into the turkey and stuffing, enjoy the holiday with your family, friends, and fellow...
1m 5K 10K Half Marathon
7
DEC
5

Westminster, CO
• 21.3 miles
$25 -$85
Ho-ho-hit the trail this holiday season at the 15th Annual Fa La La 5K, 10K & half marathon! This festive run/walk benefits A Precious Child and takes you on a scenic journey along the Big Dry...
5K 10K Half Marathon
52
DEC
26

Centennial, CO
• 46.2 miles
$30 -$45
🎉 Start Your Year on the Right Foot! 🏃‍♀️🏃‍♂️Join the New Year's Run - New Beginnings Starts Today!Kick off the new year with energy, excitement, and a community of runners ready to chase their...
1m 5K 10K Half Marathon
3
MAR
14

Severance, CO
• 40.1 miles
$15 -$95
Celebrate the luck of the Irish at Lucky Brew! All participants will receive chip timing, photos, Lucky Brew performance shirt and a great after party, complete with beverages, food, awards for...
5K 10K 15K Half Marathon
MAR
21

Golden, CO
• 20.5 miles
$20 -$85
All-Out Multicourse is proud to host our 15th Annual Spring Fever, a rewarding event for both novice and experienced athletes set against the backdrop of Table Mountain and the stunning Colorado...
5K 10K Half Marathon
33
APR
11

Littleton, CO
• 38.7 miles
$40 -$255
Welcome to the Platte River Half Marathon, Relay & 5k race, one of the most exciting and popular races in the Denver Metro Area! This race is held annually in Littleton, CO. We’re thrilled to...
5K Half Marathon
3
APR
24

Westminster, CO
• 21.3 miles
$20 -$85
Unleash your inner superhero at the 15th Annual Beat the Heat event! This year, we're calling all champions to assemble where one of Colorado's favorite trails joins one of its most glorious...
5K 10K Half Marathon
10
MAY
2

Fort Collins, CO
• 38.0 miles
$40 -$235
Early Bird Registration will open on July 1, 2026. Join us for the Colorado Marathon in Fort Collins next May! Our annual event takes place in the stunning Poudre Canyon and the gorgeous natural...
5K 10K Half Marathon Marathon
5
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