It measures approximately 2.5 by 8 miles (4.0 by 12.9 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.

Crystal Lake is adjacent to the southern reaches of the Sleeping Bear Dunes National Lakeshore.

[1] The watershed that feeds Crystal Lake is very small, and fertilizer and sewage outflows are minimal, leading to the exceptionally clear water that gives it its current name.