CASEVILLE TO PORT AUSTIN, MICHIGAN Point-to-point. Fully Paved, USATF Certified Course on Michigan’s Thumb Coast. The Rock CF Foundation and Trivium Racing are excited to bring to life the Thumb Coast Marathon: a flat, fast course featuring stunning views of Lake Huron on November 2nd, 2025. Starting in historic downtown Caseville, Michigan, this point-to-point course will travel east with a downtown finish in beautiful Port Austin, Michigan. The Full Marathon will start in Caseville and finish in Port Austin, whereas the Half Marathon will start in Sleeper State Park and finish at the same location in Port Austin. The 5K will be a loop around downtown Port Austin, featuring the same finish line as the Full and Half.