Colorado Race Calendar

Colorado Half Marathons by Date • By City

Browse all 2021 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 2021

February 2021

Sat Feb 6 All-Out Mardi Crawl Half Marathon 10K & 5K Lakewood CO
Sun Feb 7 Super Half Marathon & 5K Colorado Springs CO

March 2021

April 2021

May 2021

Sat May 1 Fruita Trail Half Marathon Fruita CO
Sun May 2 Colorado Marathon Half Marathon 10K & 5K Fort Collins 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 2020

October 2020

November 2020

Sat Nov 7 Backcountry Wilderness Half Marathon Highlands Ranch CO

December 2020

Sat Dec 5 All-Out Fa La La Half Marathon 10K & 5K Westminster CO
Sun Dec 6 Rock Canyon Half Marathon Pueblo CO