The Straits of Mackinac Shipwreck Preserve is a 148-square-mile state preserve where Lakes Michigan and Huron meet, spanning waters around Mackinaw City, St. Ignace, and nearby islands. It is especially significant for its concentration of historic shipwrecks, with at least twenty-two diveable wrecks marked by buoys and other deeper or outlying wrecks nearby. Fog, heavy shipping traffic, and the strait’s hazardous passage caused many losses, reflected in local lighthouses and in the 1965 sinking of the freighter Cedarville after a collision. The preserve also contains notable submerged geology, including Mackinac breccia formations and the drowned Mackinac Falls discovered in August 2007.