Found 251 races

🎉 Join Your Local Running Community!

Connect with runners, find training partners, and celebrate every finish together

OCT
3

Loveland, Colorado
• 34.0 miles
Experience the ultimate Colorado adventure at Boyd Lake State Park! This event pairs you and your dog for a scenic run filled with fun, beginner-friendly obstacles. It’s all about local vibes,...
2m
1
15
OCT
4

Lorton, VA
• 5.0 miles
$50 -$67
Located just south of the Capital Beltway in Lorton, this beautiful race course includes a mixture of forested and open meadow singletrack meandering through 1600 acres of the former prison...
5m 10m
OCT
4

Aurora, CO
• 10.9 miles
$10 -$15
Rocky Mountain Road Runners holds a monthly Trophy Series in the Denver area.  We provide a low-key, low-cost racing environment. Everyone is welcome to run with us! The 8mi race uses a handicap...
5K 8m
37
OCT
4

Aspen, CO
• 119.6 miles
$60 -$65
Join us on Sunday, October 4, for a Halloween themed 5.6K (3.5 mile) run or 1 mile walk beginning at Koch park and winding through the Marolt foot path and Moore open space with your furry...
1m
52
OCT
10

Breckenridge, CO
• 115.5 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
10

Fort Collins, CO
• 45.2 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
52
OCT
11

Fort Collins, CO
• 47.6 miles
This fun run is held on national coming out day this out and back Greenway 5K is here to celebrate everyone and anyone! There will be an unofficial clock and a mini award ceremony after. this is...
5K
OCT
11

Westminster, CO
• 22.9 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
86
OCT
17

Fort Collins, CO
• 43.5 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
OCT
17

Sedalia, CO
• 12.7 miles
$50 -$170
The Human Potential Running Series PresentsThe Indian Creek Trail Runs @ Indian Creek Campground The Indian Creek Trail Runs is the oldest official race of HPRS and is also known as our annual...
55K
OCT
17

Denver, CO
• 15.9 miles
$30
Participants joining our inaugural annual 5K Run/Walk will help bring clean, sustainable water solutions to communities in need and support our disaster response initiatives. We will be hosting...
5K
OCT
17

Lakewood, CO
• 15.9 miles
$65 -$90
Welcome to the Great Trailhead Foot Race at Bear Creek Lake Park!  Featuring legitimate TRAILS in the shadow of Denver's skyline, you'll love the single-track and dirt as you race 5 miles, or a...
5m 10m
60
OCT
18

Glenwood Springs, CO
• 119.4 miles
$30 -$40
Lace up your sneakers and put on your best costume—it’s time for the 3rd Annual Halloween Hustle For Charity, a family-friendly charity race that brings together a community of athletes, costumed...
1K 5K
3
OCT
18

Denver, CO
• 11.7 miles
10K Half Marathon
32
OCT
24

Arvada, CO
• 21.8 miles
$10 -$55
Voted Best of the Best in Arvada for Non Profit Events by Colorado Community Media! Join the Apex Foundation for the 6th Anniversary Trick or Trot 5K, presented by Intermountain Health! Runners...
5K
17
OCT
25

Denver, CO
• 11.2 miles
$30 -$50
The Ghosts & Goblins 5K/10K is a family, friendly event to celebrate the upcoming holiday season. Start your holiday traditions with a fun morning of fitness and friends by joining us at Denver’s...
5K 10K
52
OCT
25

Denver, CO
• 8.5 miles
The Odyssey Odyssey Fun Run is entering its 14th year. It has always been centered around having fun and exercising our bodies.  It is an all-inclusive event, which is why all the races are FREE...
1m 5K
77
OCT
31

Idaho Springs, CO
• 32.4 miles
$20
🎃 Halloween Fun Run – 5K & 1 Mile (Zombie Theme)Saturday, October 25, 2025 • 10 AM – 12 PM320 Chicago Creek Rd, Idaho Springs, CO Whether you shuffle like the undead, sprint like you're being...
1m 5K
10
OCT
31

Thornton, CO
• 61.6 miles
$40 -$60
Dress up and run spooky and silly at the I Ain't Scared (of 5k) in Thornton!  Fun music, Halloween snacks and costumes galore!!  This event only comes around once every few years when Halloween...
0m 5K
14
OCT
31

Loveland CO
• 30.5 miles
Brisk autumn running in Colorado – OH YEA! Join us for a family fun event with FIVE distance options at the beautiful Boyd Lake State Park venue. Choose your adventure! Heavy 5K, 10K, 15K (4, 7...
1m 4m 7m 10m
18