The Marine Mill, established in 1839, was the first commercial sawmill in what became the U.S. state of Minnesota. Now in ruins, it is currently a historic site managed by the city of Marine on St. Croix in partnership with the Minnesota Historical Society. It was listed on the National Register of Historic Places as the Marine Mill Site in 1970 for having state-level significance in the themes of exploration/settlement, industry, and transportation. It was nominated for being the birthplace of the region's seminal industry—lumbering—and a major landing on its crucial transportation route, the St. Croix River. The site is also a contributing property to the Marine on St. Croix Historic District.