Pottawatomie Light on Rock Island in Door County, first lit in 1836, is the oldest light station in Wisconsin and on Lake Michigan, serving one of the Great Lakes’ busiest historic routes. Its poorly built original house and detached tower were replaced in 1858 by the present limestone lighthouse, set high on a bluff with the tower built into the dwelling. Civilian keepers served until automation in 1946, and the active light remained in use until 1988. Restored to reflect its early 20th-century appearance, the site preserves original features and artifacts, includes Door County’s oldest structure, and now operates as the Pottawatomie Lighthouse Museum.