The Harvest Moon Half Distance Triathlon: This event takes place at the beautiful Boulder Reservoir on September 12, 2027 and we couldn't be more excited to be back for another year. Est. in 2000 this Colorado classic provides the veterans to beginners a challenging, affordable, and competitive race with a local flavor. Whether this is your first event of the season, or a tune-up for a summer long course triathlon, don't miss the Harvest Moon! The Aquabike portion is one of the fastest growing Aquabikes in the nation, while the duathlon is Colorado's only long-course duathlon.