Half-Marathon races in Colorado, United States — 2026 running calendar

Fall Equinox

Fort Collins, Colorado, United States

Sep 20, 2026 (Sun) – Oct 3, 2026

$75.00 - $150.00

Running

Half-Marathon 8K

Oktoberfest Run 5K/10K/13.1 DENVER/AURORA

Centennial, Colorado, United States

Sep 26, 2026 (Sat)

$30.00 - $45.00

Running

5K 10K Half-Marathon 1.6K +2

Running for Children's Rights to Both Parents - 9 of 50 Half Marathons in 50 States - Colorado

Boulder, Colorado, United States

Sep 27, 2026 (Sun)

$40.00 - $500.00

Running

Half-Marathon 5K 10K

Colorado Springs Marathon, Half, 5K, and Kids K

Colorado Springs, Colorado, United States

Oct 3, 2026 (Sat)

Free - $120.00

Running

Marathon Half-Marathon 5K 1K +11

Rim to Rim Royal Gorge Races: 5K Road Run, Trail 8 Mile, Trail Half Marathon

Canon City, Colorado, United States

Oct 3, 2026 (Sat)

$40.00 - $80.00

Running

5K 12.9K Half-Marathon 10K +2

Spooky Sprint - Denver

Littleton, Colorado, United States

Oct 3, 2026 (Sat)

$25.00 - $67.00

Running

1.6K 5K 10K Half-Marathon

Windsor Marathon, Half Marathon, 10k, 5k & 1 Mile Run

Windsor, Colorado, United States

Oct 4, 2026 (Sun)

$20.00 - $115.00

Running

Marathon Half-Marathon 10K 5K +1

Coffee Lovers Run 5K/10K/13.1 DENVER/AURORA

Centennial, Colorado, United States

Oct 10, 2026 (Sat) – Nov 28, 2026

$30.00 - $45.00

Running

5K 10K Half-Marathon 1.6K +8

Breckenridge RunFest

Breckenridge, Colorado, United States

Oct 10, 2026 (Sat) – Oct 11, 2026

$25.00 - $120.00

Running

10K 5K 1.6K Marathon +1

The Long View Marathon

Fort Collins, Colorado, United States

Oct 10, 2026 (Sat)

$35.00 - $110.00

Running

Marathon Half-Marathon 5K

Durango Marathon

Durango, Colorado, United States

Oct 11, 2026 (Sun)

$30.00 - $165.00

Running

Marathon Half-Marathon 5K

Westy Half & 5k

Westminster, Colorado, United States

Oct 11, 2026 (Sun)

$45.00 - $70.00

Running

Half-Marathon 5K