Iosco County located in Michigan's lower peninsula is bordered on the east by Lake Huron. As of the 2020 census, the population was 25,237. The county seat is Tawas City.
Iosco has traditionally been said to be a Native American word meaning "water of light", but was actually coined as a pseudo-Native American name by Henry Rowe Schoolcraft, an American geographer and ethnologist who served as the U.S. Indian agent in Michigan in the late 19th century. He named several counties and towns during the state's formative years.
A New Map of Michigan with its Canals, Roads & Distances (1842) by Henry Schenck Tanner, shows Iosco County as Kanotin, the county's name from 1840 to 1843. Several nearby counties are also shown with names that would later be changed.
Iosco County is home to Tawas Point State Park.
The county was created by the Michigan Legislature in 1840 as Kanotin County, and renamed Iosco County in 1843. It was administered by a succession of other Michigan counties before the organization of county government in 1857. A majority of the population was Ojibwe. The area offered shelter from tall white pines and food from the river and lake. Iosco County was cut from a piece of land ceded by the Ojibwe to the U.S. government. When the lumber boom hit, many more people moved to the area.
The 400-acre Alabaster Historic District, listed on the National Register of Historic Places, is associated with an operating gypsum open-pit mine south of Tawas City. The large company town included internal rail lines for transportation and a tramway extending over Lake Huron on long piers for loading gypsum onto ships. Started in 1862, the mine supplied gypsum for temporary buildings constructed in Chicago at the World Columbian Exposition of 1893. Two companies continue to mine gypsum in Iosco County.
In 2009, Alabaster Township formed the nonprofit Alabaster Wind Power Development Corp. to conduct the necessary two-year studies of wind data at this site as a potential location for development of wind turbines. It proposed using 10 large tramway platforms that extend more than 6,000 feet into the lake to gauge winds. The turbines could be built on the tramways. At the time, the federal government was offering subsidies for such studies and development of alternative energy projects.