Mud Mountain Dam Marathon

The Mud Mountain Dam Marathon event, organized by the Tacoma City Marathon Association, is held in Buckley, Washington. The 2025 fall event features a half marathon and a 5K, as the full marathon is not scheduled due to pending completion of the Spiketon Foothills connection bridge. The half marathon starts in South Prairie and follows a gradual downhill, fully paved course along the Foothills Rail Trail, passing through farmland and forest alongside the Carbon River, finishing at the historic McMillin Bridge with a net elevation loss of 339 feet.

The 5K is an out-and-back route on the Foothills Trail, starting and finishing at the McMillin Foothills Trail Bridge. The event offers scenic views, well-supported aid stations, and commemorative medals for finishers. Visit the organization's website for the most recent information.