Rule 4. The following described area is established as the Thumb Area Great Lakes state bottomland preserve: That area of bottomlands of Lake Huron, extending upward and including the surface of the water with a western boundary beginning at the light on the end of the breakwater in Port Austin, thence extending northerly along Loran-C coordinate 8970-X-30910; thence easterly along Loran-C coordinate 8970-Y-49150; thence southerly along Loran-C coordinate 8970-X-30730; thence westerly along Loran-C coordinate 8970-Y-49335.5 to the south boundary of Wagener County Park, thence northerly and westerly along the ordinary high water mark to the point of beginning, which area contains 276 square miles, more or less.
Mich. Admin. Code R. 299.6004