Boulder Marathons Events

Boulder Peak Triathlon, Duathlon, & Aquabike

Boulder Reservoir 12 Jul 2026

Colorado Triathlon (Sprint, Olympic, Duathlon, & Aquabike)

Boulder Reservoir 6 Jun 2026

Boulder Rez Half Marathon

Boulder Reservoir 11 Apr 2026

Chelsea Sodaro: An Unlikely Journey to Triathlon, Motherhood, and Ironman World Champion

Chautauqua Community House 18 Mar 2026

Boulder Stroke and Stride Series

Boulder Reservoir 4 Jun 2026

Harvest Moon Long Course Triathlon

Boulder Reservoir 31 May 2026

2026 World Cancer Day 1M 5K 10K 13.1 26.2

Boulder 1 Feb 2026

2026 Full Moon Challenge 12K and 12M

Boulder 7 Feb 2026