The Mackinaw State Forest is a 717,500-acre (2,904 km2) forested area owned by the U.S. state of Michigan and operated by the Michigan Department of Natural Resources. It is located in the northern area of the Lower Peninsula within the eight counties of Alpena, Antrim, Charlevoix, Cheboygan, Emmet, Montmorency, Otsego, and Presque Isle. The forest is served by Interstate 75, U.S. Highway 23 (US 23), and US 131.