CO · October 2026–2027
Half Marathons in Colorado in October
7 half marathons in Colorado are on the calendar for October 2026–2027, in Fort Collins, Mancos, Centennial, Boulder and more. Tap a race for the course, weather, past results and how to register.
Blue Sky Trail Marathon & Half Marathon · Fort Collins, Colorado
Mancos Cowboy Half Marathon, 5K, and Fun Run · Mancos, Colorado
Halloween Trick or Trot Run 5K/10K/13.1 DENVER/AURORA · Centennial, Colorado
PB&J Fuel Run 5K/10K/13.1 DENVER/AURORA · Centennial, Colorado
2027 Boulderthon · Boulder, Colorado
2027 Westminster Half Marathon & 5K · Westminster, Colorado
2027 The Long View Marathon · Fort Collins, Colorado