The Rock CF Thumb Coast Marathon, Half Marathon and 5K

The Rock CF Thumb Coast Marathon, Half Marathon and 5K is run in Caseville, Michigan, on November 8, 2026. The marathon (26.2 miles) starts at 8 a.m., the half marathon (13.1 miles) at 8:30 and the 5K at 9. Organized by the Rock CF Foundation and Trivium Racing, the course is USATF-certified, fully paved and flat, with views of Lake Huron along Michigan's Thumb Coast.

The layout is point to point: the marathon runs from Caseville to Port Austin, the half starts at Sleeper State Park and finishes in the same place, and the 5K loops through downtown Port Austin to that shared finish line. Flat and certified is exactly what you want for a qualifying attempt or a personal best, so hold goal pace through the back half of your longest training runs rather than fading. Point-to-point starts need planning for transport and drop bags, so sort that out the day before.