In the 1850s the Lake Erie islands were used for grape production, earning them the nickname wine islands. The Lonz Winery on Middle Bass Island was a familiar landmark from the early twentieth century, and after the winery closed the state bought the complex and opened Middle Bass Island State Park in 2001. In 2024 the historic Lonz Mansion was restored and opened for overnight stays, with a self-guided tour of the first floor about the Lonz family and their winery. The park office is open from May 1 to October 15 with hours that vary, and it is closed Monday through Wednesday.