Crystal Lake, the largest lake of this name in Michigan, is located near Lake Michigan in Benzie County about 25 miles (40 km) southwest of Traverse City and about 2 miles (3 km) northeast of Frankfort at (44°39′N86°09′W). It measures approximately 2.5 by 8 miles (4 by 13 km), and has a maximum depth of 165 feet (50 m). At 9,854 acres (40 km²), it is Michigan's ninth largest inland lake. Up to and through the American Civil War years Crystal Lake was known as "Cap Lake" due to the frequent whitecaps visible on its surface.