Indiana Dunes State Park is an Indiana State Park located in Porter County, Indiana, United States, east of Chicago. The park is bounded by Lake Michigan to the northwest and is surrounded by as well as within the authorized boundaries of Indiana Dunes National Park, a unit of the National Park Service; the NPS owns the water from the ordinary high water mark to offshore. The Dunes Nature Preserve makes up the bulk of eastern part of the park, and includes most of the park's hiking trails and dune landscape. This was one of the first places Richard Lieber considered when establishing the Indiana State Park system. Like all Indiana state parks, there is a fee for entrance. Indiana Dunes State Park was established in 1925 and designated a National Natural Landmark in 1974. Preserving the Indiana Dunes has resulted from the efforts of many citizens and politicians. In 2018–2019, Indiana Dunes was the most-visited state park, with more than 1.3 million visitors. Geology The beaches were formed by winds coming off Lake Michigan, which drop sand when the wind hits plants, dunes, and hills. As the lake level of Lake Michigan dropped at the end of the Ice Age, the shoreline receded, and new dunes were formed along the lakeshore. Vegetation took over the previous dunes, and eventually forests grew on top of them. There are "blowouts" along the dunes, where dead stumps were revealed after the wind blew away the sand from on top of them; the most notable such blowout is Big Blowout. History Native Americans used the area for years, primarily the Potawatomi and Miami people. The Dunes were along trade routes used by Native Americans. In the early 19th century, the state park area was home to the settlements of Petit Fort and City West. Notable attractions Sand dunes Singing sand Smelt fishing Haunted shores (Diana of the Dunes) Birding Hiking Facilities and activities Swimming and sunbathing: A small portion of the shoreline is set aside as a public swimming beach and is protected by lifeguards between Memorial and Labor Day weekends. It is a clean, all sand beach. The remainder of the beach (approximately ) is open for sunbathing, beach combing, and other similar activities. Dogs are permitted on the non-swimming portion of the beach, so long as they are kept on a short leash and any feces is promptly and safely removed from