Indiana Dunes National Park is a United States national park located in northwestern Indiana managed by the National Park Service. It was authorized by Congress in 1966 as the Indiana Dunes National Lakeshore and was redesignated as the nation's 61st national park on February 15, 2019. The park runs for about 20 miles along the southern shore of Lake Michigan; it covers 15,349 acres of various acreage. Along the lakefront, the eastern area is roughly the lake shore south to U.S. 12 or U.S. 20 between Michigan City, Indiana, on the east and the ArcelorMittal steel plant on the west. A small extension south of the steel mill continues west along Salt Creek to Indiana 249. The western area is roughly the shoreline south to U.S. 12 between the Burns Ditch west to Broadway in downtown Gary, Indiana. In addition, there are several outlying areas, including Pinhook Bog, in LaPorte County to the east; the Heron Rookery in Porter County, the center of the park; and the Calumet Prairie State Nature Preserve and the Hobart Prairie Grove, both in Lake County, the western end of the park.