Marathon races in Colorado, United States — 2026 running calendar

The Steamboat Marathon

Steamboat Springs, Colorado, United States

Jun 7, 2026 (Sun)

Running

Marathon Half-Marathon 10K

Weld Your Mettle Running Festival

Eaton, Colorado, United States

May 30, 2026 (Sat) – May 31, 2026

Trail running, Running

Ultra 6.9K 22.5K Marathon +7

2026 CKF Cape Town Marathon

Aspen, Colorado, United States

May 24, 2026 (Sun)

Running

Marathon

Colfax Marathon

Lone Tree, Colorado, United States

May 17, 2026 (Sun)

Running

Marathon

Girls on the Run Rockies Colfax SoleMates 2026

Denver, Colorado, United States

May 17, 2026 (Sun)

Running

Marathon Half-Marathon

Race Through Colorado 1M, 5K, 10K, 13.1, 26.2 - Now Only $20!

Denver, Colorado, United States

Mar 28, 2026 (Sat) – Dec 31, 2026

$20.00

Running

1.6K 5K 10K Half-Marathon +1