Wurtsmith Air Force Base is a decommissioned United States Air Force base in Iosco County, Michigan. Near Lake Huron, it operated for seventy years, from 1923 until decommissioned in 1993. On January 18, 1994, Wurtsmith was listed as a Superfund site, due to extensive groundwater contamination with heavy metals, polycyclic aromatic hydrocarbons, volatile organic compounds, including trichloroethylene, 1,1-dichloroethane, 1,1,1-trichloroethane, and vinyl chloride. In 2010, Per- and polyfluoroalkyl substances contamination was discovered, and as of 2022 remediation is still ongoing.

Iosco County is a county in the U.S. state of Michigan; its eastern border is formed by Lake Huron. As of the 2020 census, the population was 25,237. The county seat is Tawas City.