Half Marathons in Colorado — 2026

There are 80 half marathons in Colorado scheduled for 2026. The next is the Mancos Cowboy Half Marathon, 5K, and Fun Run in Mancos on October 24. Colorado half marathons run primarily October through February.

Horsetooth Half Marathon - Presented by Fort Collins Connexion

Sun, Apr 18 · Fort Collins, CO Fort Collins

Half MarathonHalf Marathon

From $75 Open

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All-Out Beat the Heat

Sat, Apr 24 · Westminster, CO Westminster

VIRTUAL 5K5KVIRTUAL 5K +9

From $20 Open Closing Soon

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Bigfoot Half Marathon

Sat, Apr 24 · Estes Park, CO Estes Park

Kids Dash5K Run/Walk5K Run/Walk +2

From $30 Open

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Run for Donut DENVER/AURORA

Sat, Apr 24 · Centennial, CO Centennial

Family 1 Mile Fun Run5K/10K/13.1 Eco-Registration (No Shirt)Virtual Run Registration +3

From $30 Open

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Coffee Lover Run DENVER/AURORA

Sat, Apr 24 · Centennial, CO Centennial

Family 1 Mile Fun Run5K/10K/13.1 Eco-Registration (No Shirt)Virtual Run Registration +3

From $30 Open

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Longmont Half & 5k (LM Half)

Sun, May 2 · Longmont, CO Longmont

5k5kHalf Marathon +1

From $35 Open

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Run for Chocolate 5k/10k/13.1 DENVER/AURORA

Sat, May 8 · Centennial, CO Centennial

Family 1 Mile Fun RunVirtual Run Registration5K Registration +3

From $30 Open

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Vallecito Lake Heavy Half

Sat, May 15 · Bayfield, CO Bayfield

Vallecito Lake Heavy Half MarathonVallecito Lake Heavy Half Marathon

From $75 Closed

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SuperHeroes Run DENVER/AURORA

Sat, May 29 · Centennial, CO Centennial

Family 1 Mile Fun Run5K Registration5K/10K/13.1 Eco-Registration (No Shirt) +3

From $30 Open

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Colorado 13er (Half Marathon/10k/5k)

Sun, Jun 6 · Louisville, CO Louisville

5k5k10k +3

From $30 Open

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All-Out Summer Breeze

Sat, Jun 12 · Arvada, CO Arvada

5KVIRTUAL 5K5K +9

From $20 Open

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Red, White and Brew 5k, 10k & Half Marathon

Sat, Jun 19 · Windsor, CO Windsor

1 Mile Fun Run1 Mile Fun Run5k Ruck +9

From $15 Closed

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Run Juneteenth Day 5K/10K/13.1 DENVER/AURORA

Sat, Jun 19 · Centennial, CO Centennial

Family Fun Run 1 MileVirtual Run Registration (5K/10K/13.1)5K Registration +3

From $30 Open

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Treat Trot - Denver

Sat, Jun 19 · Denver, CO Denver

5K5K10K +11

From $17 Open 5 spots left

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Treat Trot Colorado Springs

Sun, Jun 20 · Colorado Springs, CO Colorado Springs

5K5K10K +11

From $17 Open 5 spots left

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Slacker Half Marathon-Relay-4-Mile Races

Sat, Jun 26 · Georgetown, CO Georgetown

4 Mile - Military VeteranVirtual 4 Mile4-Mile +11

From $35 Closed

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Grin & Bear It

Sat, Jul 10 · Crested Butte, CO Crested Butte

15 km Out and Back15 km Out and BackMountain Bike +3

From $75 Closed 74 spots left

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All-Out Dog Days

Sat, Jul 10 · Westminster, CO Westminster

VIRTUAL 5K5KVIRTUAL 5K +9

From $20 Open

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Summer Splash Prairie Dog Half, 10k, & 5k

Sat, Jul 17 · Castle Rock, CO Castle Rock

5k5k10k +3

From $25 Open

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Popsicle 5K/10K/Half - Colorado Springs

Sat, Jul 31 · Colorado Springs, CO Colorado Springs

Virtual 5K5K-No Shirt5K +15

From $25 Closed

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All-Out Runapalooza

Sat, Aug 7 · Arvada, CO Arvada

VIRTUAL 5K5K5K +9

From $20 Open

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Erie Half & 5k

Sun, Aug 15 · Erie, CO Erie

5k5kHalf Marathon +1

From $30 Open

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Byers Peak Stampede Half Marathon & 5K Run

Sat, Aug 21 · Fraser, CO Fraser

5K5KHalf Marathon +1

From $45 Open

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Pioneer Prairie Dog Half, 10k & 5k

Sun, Aug 22 · Westminster, CO Westminster

5k5k10k +3

From $25 Open

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TBK Bank Thirsty 13 Half Marathon

Sat, Aug 28 · Durango, CO Durango

Race Plus BrewfestJust The Race -- No Brewfest TicketJust The Race -- No Brewfest Ticket +1

From $85 Closed

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Labor Day Half Marathon

Mon, Sep 6 · Parker, CO Parker

5K5K10K +5

From $27 Open

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Autumn Run

Sat, Sep 18 · Buena Vista, CO Buena Vista

5K5K10K +3

From $30 Closed 75 spots left

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All-Out Fall Fest

Sat, Sep 18 · Westminster, CO Westminster

5KVIRTUAL 5KVIRTUAL 5K +9

From $20 Open

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Westy Half & 5k

Sun, Oct 10 · Westminster, CO Westminster

5k5kHalf Marathon +1

From $30 Closed

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50 States Half Marathon Club General Membership

Fri, Feb 10 · Colorado Springs, CO Colorado Springs

50 States Half Marathon Club General Membership

From $85 Open

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Fifty States Half Marathon Club Life Membership

Sat, Feb 11 · Colorado Springs, CO Colorado Springs

Fifty States Half Marathon Club Life Membership

From $429 Open

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