Rockport State Park

In 1914, the Great Lakes Lime and Stone Company opened one of the largest stone quarries of its time. Located a few miles north of Alpena, Michigan, it now exists as Rockport State Park, a 4,237 acre natural area with a deep-water protected harbor, and 300-acre limestone quarry.

This undated photo shows the massive conveyor belt pier that loaded rocks onto docked transport ships.