Boulder close

Half Marathon Calendar near Boulder 2025-2026

Explore the top half marathons near Boulder for 2025-2026! We've gathered 32 exciting races in the area. Check out our detailed list below to find your next local race.

December 2025
Dec
6
Sa

All-Out Fa La La
5 km 10 km Half Marathon
Dec
7
Su

RunDenver Series
5 km 4 mi 10 km 13 mi
January 2026
Jan
10
Sa

Polar Prowl
5 km 10 km Half Marathon
February 2026
Feb
15
Su

Ralston Creek Half Marathon
5 km Half Marathon
Feb
22
Su

Mardi Crawl
5 km 10 km Half Marathon
Feb
28
Sa

Bodies Race Company - City Park West
5 km 10 km 13 mi
March 2026
Mar
1
Su

That Dam Run Half Marathon
5 km 10 km 13 mi
Mar
22
Su

All-Out Spring Fever
5 km 10 km Half Marathon
April 2026
Apr
11
Sa

Boulder Rez Half
5 km 10 km Half Marathon
Apr
12
Su

Spring Fling Prairie Dog Half Marathon
5 km 10 km 13 mi
Apr
18
Sa

All-Out Beat the Heat
5 km 10 km Half Marathon
Apr
25
Sa

Runs With Scissors Races
Half Marathon Marathon 50 km
May 2026
May
3
Su

Longmont Half
5 km Half Marathon
May
10
Su

Bodies Race Company - Broomfield
5 km 10 km Half Marathon
May
15-17
Fr - Su

Denver Colfax Marathon
5 km 10 mi 13 mi 26 mi
June 2026
Jun
7
Su

Colorado 13er Half Marathon
5 km 10 km 13 mi
Jun
13
Sa

All-Out Summer Breeze
5 km 10 km Half Marathon
Jun
13
Sa

Barr Lake Trail Race
Trail Run 5 km 15 km ... 30 km 50 km
July 2026
Jul
11
Sa

All-Out Dog Days
5 km 10 km Half Marathon
Jul
11
Sa

Bodies Race Company - Denver
5 km 10 km Half Marathon