Colorado Race Calendar

Colorado Half Marathons by Date • By City

Browse all 2023-2024 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.

September 2023


Sat Sep 2	Sloan's Lake Search Party Marathon & Half Marathon Hourly Loop Race	Denver CO
Sun Sep 3	Breck Crest Mountain Marathon Half Marathon & 10k	Breckenridge CO
Sun Sep 3	Calarat Challenge Trail Running Festival Half Marathon 10k & 5k	Jamestown CO
Mon Sep 4	Labor Day Half Marathon	Parker CO
Sat Sep 9	Black Squirrel Half Marathon	Fort Collins CO
Sat Sep 9	Ned Ned Run Half Marathon 10k & 5k	Nederland CO
Sat Sep 9	Trail Sisters Women's Half Marathon	Buena Vista CO
Sat Sep 16	All-Out Fall Fest Marathon Half Marathon 10K & 5K	Westminster CO
Sat Sep 16	Autumn Color Run Half Marathon 10k 5k & 1M	Buena Vista CO
Sat Sep 16	Mountain RATS 55k Marathon & Half Marathon	Eagle CO
Sat Sep 16	Run the Rockies Half Marathon & 10k	Frisco CO
Sun Sep 17	Adams Half & 5k	Brighton CO
Sun Sep 17	Fall Equinox Marathon Half Marathon & 5M	Fort Collins CO
Sun Sep 17	Nun Run Half Marathon 10k & 5k	Centennial CO
Sat Sep 23	Beulah Challenge Half Marathon 10k & 5k	Beulah CO
Sat Sep 23	Golden Leaf Half Marathon	Aspen CO
Sat Sep 23	John Wayne Grit Series – Ridgway Half Marathon & 5k	Ridgway CO
Sat Sep 23	Pioneer Prairie Dog Half Marathon 10K & 5K	Westminster CO
Sat Sep 23	Snow Mountain Ranch Trail Festival Half Marathon	Granby CO
Sun Sep 24	Bear Chase Race Half Marathon & 10k	Lakewood CO
Sun Sep 24	Red Feather Trail Jamboree 50k & Half Marathon	Red Feather Lakes CO
Sun Sep 24	Sunlight Showdown Half Marathon	Glenwood Springs CO
Sat Sep 30	Colorado Springs Marathon Half Marathon & 5k	Colorado Springs CO
Sat Sep 30	Deep Creek Trail Half Marathon	Telluride CO
Sat Sep 30	The Rad Dirt Fest 50k & Half Marathon	Trinidad CO

October 2023


Sun Oct 1	Colorado Brewery Running Series – New Belgium Brewing Half Marathon	Fort Collins CO
Mon Oct 2	Center of the Nation Series – Day 1 Marathon & Half Marathon	Sterling CO
Sat Oct 7	Breckenridge Road Marathon Half Marathon & 10k	Breckenridge CO
Sat Oct 7	Castle Rock Trail Festival 50k Half Marathon 10k & 5k	Castle Rock CO
Sat Oct 7	Rim to Rim Royal Gorge Races Half Marathon	Canon City CO
Sun Oct 8	Boulderthon Marathon & Half Marathon	Boulder CO
Sun Oct 8	Windsor Marathon Half Marathon 10k & 5k	Windsor CO
Sat Oct 14	Long View Marathon & Half Marathon	Fort Collins CO
Sat Oct 14	Mancos Cowboy Half Marathon & 5k	Mancos CO
Sun Oct 15	Westy Half & 5k	Westminster CO
Sun Oct 29	All-Out Kooky-Spooky Half Marathon 10k 5k & 1M	Golden CO

November 2023


Sat Nov 4	Bridge Burner Ultra 50k 30k & Half Marathon	Canon City CO
Sat Nov 4	HRCA Backcountry Wilderness Half Marathon	Highland Ranch CO
Sun Nov 5	Rim Rock Run Marathon & Half Marathon	Fruita CO
Mon Nov 6	Southwest Series Day 2 Marathon Half Marathon & 5k	Durango CO

December 2023


Sat Dec 2	Colorado Cold Rush 50k & Half Marathon	Colorado Springs CO
Sat Dec 2	All-Out Fa La La Half Marathon 10K & 5K	Westminster CO
Sun Dec 3	Rock Canyon Half Marathon	Pueblo CO
Sun Dec 10	Four Corners Quad Keyah Marathon Half Marathon & 5k	Four Corners Monument CO

January 2024


Sat Jan 6	All-Out Polar Prowl Half Marathon 10k & 5k	Arvada CO
Sun Jan 14	Arctic Prairie Dog Half – Westminster Half Marathon 10k & 5k	Westminster CO

February 2024


Sun Feb 11	All-Out Mardi Crawl Half Marathon 10K & 5K	Arvada CO
Sun Feb 11	Super Half Marathon and Game Day 5k	Colorado Springs CO
Sun Feb 18	Stories Ultra 6H Half Marathon & 10k	Colorado Springs CO

March 2024


Sat Mar 9	Run Through Time Marathon Half Marathon & 2M	Salida CO
Sun Mar 17	All-Out Spring Fever Half Marathon 10K & 5K	Golden CO
Sun Mar 24	Spring Equinox Half Marathon & 4M	Fort Collins CO

April 2024

Sat Apr 13	All-Out Beat the Heat Marathon Half Marathon 10K & 5K	Westminster CO
Sun Apr 14	Desert RATS Trail Running Festival Half Marathon & 10k	Fruita CO
Sun Apr 14	Horsetooth Half Marathon	Fort Collins CO
Sun Apr 14	Platte River Half Marathon & Relay	Littleton CO
Sun Apr 14	Spring Fling Prairie Dog Half Marathon 10K & 5K	Arvada CO
Sat Apr 27	NOCO Half Marathon & 10k	Loveland CO
Sat Apr 27	Runs with Scissors Races 50k Marathon & Half Marathon	Brighton CO

May 2024


Sun May 5	Colorado Marathon Half Marathon 10K & 5K	Fort Collins CO
Sat May 11	Valkyrie Trail Race Half Marathon	Colorado Springs CO
Sat May 18	Mine Shaft Half Marathon & Endure 12-Hour & 24-Hour Challenges	Divide CO
Sun May 19	Denver Colfax Marathon Half Marathon 10M & Relay	Denver CO
Sun May 26	Spirit Trail Run Marathon Half Marathon & 8k	Buena Vista CO

June 2024


Sat Jun 1	Revel Rockies Marathon & Half Marathon	Evergreen CO
Sun Jun 2	Colorado 13er Half Marathon 10k & 5k	Louisville CO
Sun Jun 2	Steamboat Marathon Half Marathon & 10K	Steamboat Springs CO
Sat Jun 8	All-Out Summer Breeze Half Marathon 10k 5k & 1M	Arvada CO
Sun Jun 16	Estes Park Marathon & Half Marathon	Estes Park CO

July 2024


Thu Jul 4	Longmont Half Marathon & 5K	Longmont CO
Sat Jul 13	All-Out Dog Days Half Marathon 10K & 5K	Westminster CO
Sat Jul 20	Prairie Dog Half Marathon 10K & 5K	Castle Rock CO

August 2024


Sat Aug 3	All-Out Runapalooza Half Marathon 10K & 5K	Arvada CO
Sat Aug 3	Rocky Mountain Half Marathon	Estes Park CO
Sat Aug 17	Mount Sneffels Marathon & Half Marathon	Ouray CO