raceIQ

Marathons in Colorado

9 upcoming marathons in Colorado, with dates and field depth before you enter.

All races5K races 25110K races 114Half marathons 95Marathons 9Ultramarathons 6 Races near me
Most competitive fields

Ranked by how fast the front of the field ran in recent editions, compared with every race we track at that distance.

  1. 1Rock Canyon Half Marathon- 40th Anniversary Run!Sun, Dec 6Pueblo5KMarathon Competitive
  2. 2The Colorado MarathonSun, May 2Fort Collins5K10KHalf marathonMarathon Local
  3. 3The Steamboat MarathonSun, Jun 6Steamboat Springs10KHalf marathonMarathon
  4. 4Colorado Springs Marathon, Half, 5K, and Kids KSat, Oct 2Colorado Springs5KHalf marathonMarathon
  5. 5Weld Your Mettle Running FestivalSat, Jun 5EatonMarathon

Which of these could you place in? raceIQ ranks them by where your pace would finish, in your age group and gender.

Find your races

December 2026

March 2027

May 2027

June 2027

August 2027

October 2027