Ultramarathons in Colorado

6 upcoming ultramarathons in Colorado, with dates and field depth before you enter.

All races 5K races 251 10K races 114 Half marathons 95 Marathons 9 Ultramarathons 6 Races near me

By city

Colorado Springs (40)Denver (38)Centennial (29)Arvada (14)Fort Collins (13)Grand Junction (13)Westminster (13)Golden (7)Louisville (7)Boulder (5)Highlands Ranch (5)Littleton (5)Longmont (5)

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

November 2026

December 2026

Sat, Dec 5Sawmill Trail RunsPineUltra

April 2027