Oscoda County was a part of the following counties prior to 1881: Mackinac County (1840-1853); Cheboygan County (1853-1857); Alpena County (1857-1858); Iosco County (1858-1869) and Alcona County (1869-1881).
Oscoda County is located in the central, northeastern section of Michigan's Lower Peninsula. Oscoda County, Michigan, was created April 1, 1840 from Mackinac County and organized in 1881. Records before 1881 may be located in the counties of Iosco, Cheboygan, Alpena, or Alcona. The area, originally ceded in 1819 by the Indians in the Treaty of Saginaw, began developing during the lumber era. However, it did not grow much due to the lack of railroad development. Only one rail line was built at Comins in the 1890's. Today, the county remains sparsely populated and is primarily outdoor recreation area, offering the Au Sable River, Huron National Forest, and Oscoda State Forest. The U.S. Census Bureau estimated the 2005 population at 9,298 people. The county encompasses 565 square miles. Although Mio is the county seat, Oscoda County has no officially organized village or city.The word "Oscoda" was coined by the Michigan historian, Henry R. Schoolcraft when he visited the area in the mid 1800's, originating from two Indian words: "ossin," meaning: stones or pebbles, and "muskoda," meaning: prairie. Together, they signify a "stony prairie."