The Bellingham Bay Marathon, Half Marathon, 10K, and 5K are a group of races designed by runners for runners and walkers. Founded in 2007 by the Bellingham Bay Swim Team, BBM delivers a fun, highly personal, authentic race experience. 100% of net proceeds benefit Whatcom County youth non-profit organizations. Often called one of the most beautiful races in the Pacific Northwest, the Bellingham Bay Marathon takes place the last Sunday of September.