Colorado Race Calendar

Colorado Half Marathons by Date • By City

Browse all 2021-2022 Colorado half marathons by month below. For each race, you’ll find course maps, elevation profiles, runner reviews, and how to sign up.


When you view a race, you’ll also find contact info if you’re having problems with your registration or need to contact the race directors.

January 2022

February 2022

March 2021

April 2021

May 2021

Sat May 1 Fruita Trail Half Marathon Fruita CO
Sat May 8 Carbon Valley Half Marathon Firestone CO
Sat May 8 Mine Shaft Half & Tommyknocker Ultras Golden CO
Sat May 15 Vallecito Lake Heavy Half Bayfield CO
Sun May 23 Barr Lake Half Marathon & 15K Brighton CO
Sat May 29 Valkyrie Trail Marathon Half Marathon 50K & 4-Mile Colorado Springs CO

June 2021

Sat Jun 5 Bergen Peak Half Marathon Evergreen CO
Sat Jun 5 Revel Rockies Marathon & Half Marathon Evergreen CO
Sun Jun 6 Boulder Rez Half Marathon 10K & 5K Boulder CO
Sun Jun 6 Colorado 13er Half Marathon 10K & 5K Louisville CO
Sun Jun 6 Steamboat Marathon Half Marathon & 10K Steamboat Springs CO
Sat Jun 12 South Park Trail Marathon & Half Marathon Fairplay CO
Sat Jun 12 Steamworks Half Marathon Durango CO
Sat Jun 19 Mountain Ridge Half Marathon & 10K Highlands Ranch CO
Sun Jun 20 Estes Park Marathon Half Marathon 10K & 5K Estes Park CO
Sat Jun 26 All-Out Summer Breeze Half Marathon 10K 5K & 1-Mile Arvada CO
Sat Jun 26 Slacker Half Marathon 4-Mile & Relay Georgetown CO

July 2021

Sun Jul 4 Longmont Half Marathon & 5K Longmont CO
Sat Jul 17 All-Out Dog Days Half Marathon 10K & 5K Westminster CO
Sat Jul 17 Prairie Dog Half Marathon 10K & 5K Castle Rock CO
Sun Jul 18 Black Hawk Half Marathon & 10K Golden CO
Sun Jul 18 Sunlight Showdown Half Marathon Glenwood Springs CO
Sat Jul 31 Rocky Mountain Half Marathon Estes Park CO
Sat Jul 31 Winter Park Half Marathon & 5K Winter Park CO

August 2021

September 2021

Mon Sep 6 Labor Day Half Marathon Parker CO
Sat Sep 11 Black Squirrel Half Marathon Fort Collins CO
Sat Sep 11 Ned*Ned Half Marathon 10K & 5K Nederland CO
Sun Sep 12 Breckenridge Marathon Half Marathon & 10K Breckenridge CO
Mon Sep 13 Center of the Nation Marathon Half Marathon 10K & 5K – Day 1 Sterling CO
Sat Sep 18 All-Out Fall Fest Marathon Half Marathon 10K & 5K Westminster CO
Sat Sep 18 Autumn Color Run Half Marathon 10K & 5K Buena Vista CO
Sat Sep 18 Golden Leaf Half Marathon Aspen CO
Sat Sep 18 Mountain Rats Marathon Half Marathon & 55K Eagle CO
Sun Sep 19 Equinox Marathon Half Marathon & 5-Mile Fort Collins CO
Sun Sep 19 Snow Mountain Ranch Trail Running Festival Granby CO
Sat Sep 25 Pioneer Prairie Dog Half Marathon 10K & 5K Westminster CO
Sun Sep 26 Adams Half Marathon & 5K Brighton CO
Sun Sep 26 Bear Chase Trail Half Marathon & 10K Lakewood CO

October 2021

Sat Oct 2 Deep Creek Trail Half Marathon Telluride CO
Sun Oct 3 Long View Marathon & Half Marathon Fort Collins CO
Sun Oct 3 'Rad Dirt Fest Half Marathon & Ultras Trinidad CO
Sun Oct 3 Rim to Royal Gorge Half Marathon Cañon City CO
Sun Oct 10 Boulderthon Marathon & Half Marathon Boulder CO
Sun Oct 10 Windsor Marathon Half Marathon & Heavy 10K Windsor CO
Sat Oct 16 Aspen Valley Marathon Half Marathon & 5K Aspen CO
Sun Oct 17 Colfax Marathon Half Marathon 10-Mile & Relay Denver CO
Sun Oct 24 Colorado Marathon Half Marathon 10K & 5K Fort Collins CO
Sun Oct 24 Westy Half & 5K Westminster CO
Sun Oct 31 All-Out Kooky-Spooky Half Marathon 10K & 5K Golden CO

November 2021

Sat Nov 6 Backcountry Wilderness Half Marathon Highlands Ranch CO
Sat Nov 6 Rim Rock Marathon & Half Marathon Grand Junction CO
Mon Nov 8 Southwest Series Marathon Half Marathon 10K & 5K – Day 2 Durango CO
Sun Nov 14 Horsetooth Half Marathon Fort Collins CO

December 2021

Sat Dec 4 All-Out Fa La La Half Marathon 10K & 5K Westminster CO