(Iowa)
Banner Lakes at Summerset State Park is a 222-acre (90 ha) state park in Warren County, Iowa, United States, near the city of Indianola. Opened in 2004, the park is located on the site of a 1930s coal mine; its two namesake lakes were formed from the remnants of the mine. (Ref: https://en.wikipedia.org/wiki/Banner_Lakes_at_Summerset_State_Park)