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
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.
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 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 the shores.
Beach house with concessions during summer season.
Observation platform near the top of Mt. Tom. Looking west, Chicago can be seen above the forested sand dunes. Gary, Indiana, is also visible.
Birdwatching:
The Nature Center is a year-round facility that has a wildlife observation window, library, and a large auditorium. An interpretive naturalist provides public hikes and programs.
Cycling is not permitted everywhere within the park, but the Calumet Trail runs through the park and provides cycling opportunities in the park as well as access to Indiana Dunes National Park and some neighboring communities.
The campground was totally rebuilt in 2004. It has 140 campsites laid out on sand with new, level, asphalt pads, 50-amp electrical hook-ups, and picnic tables. Drinking water hydrants are located throughout the campground. The roads were newly laid out and paved in 2004, and are arranged in several connecting loops. Most of the trees were spared during the rebuilding so that many sites have full or partial shade. There are two large newly built shower house/restroom structures. There is a short, level forest path to the swimming beach.
Dunes Nature Preserve
The Nature Preserve covers the eastern 2/3 of the state park,. It is accessible only on foot. All eight of the park's trails enter the nature preserve, offering easy to rugged experiences amongst the dunes. The highlights of the preserve include:
The Tremonts: Mt. Tom, above lake level; Mt. Holden, above lake level; and Mt. Jackson above lake level.
* Trail 8 goes up and over all three of the high dunes. It is long from the Wilson Shelter, over the high dunes, ending on the beach at the Pavilion and Beach House.
* Trail 10 is the longest at, but among the easier, listed as a moderate trail. It begins at the Pavilion and Bathhouse, traveling east along the open beach. About down the beach, is the Beach House Blowout. An additional further is the Furnessville Blowout. At about half way is the eastern boundary of the park, at which point the trail enters the dunes through an area called Paradise Valley. From there, the trail parallels a branch of the Dunes Creek, passing through the Pinery and along the marsh. The Bird Observation Tower is accessible from this trail. About from the Observation Tower, the trail ends at the Nature Center.
Designated a National Natural Landmark in 1974, the preserve also contains the Ancient Pines Nature Area, a prehistoric forest now exposed by dune blowouts.
Blowouts
Blowouts are formed by the on-shore winds of Lake Michigan. The winds move sand and pile it into dunes. As the dunes form, plants begin to take hold, stabilizing the sand. Beach grasses form a large underground system of roots. This root system, creates stable areas of sand, from which the dune can grow. Slowly other plants take root in the protected areas, including bearberry and small evergreens. Over time, larger plants like sumac, sand cherry, cottonwood, and juniper take hold and replace the grasses and smaller plants. When a nick forms in this armor of roots and plants, the area can become a blowout. First, open sand becomes accessible to the wind. This can be by animal trails or by human footpaths. A tree could fall in a strong wind, exposing the underlying sand. When this happens, the wind once again works on the loose sand. It undercuts the other roots, and begins moving sand southward. If the winds are strong enough or given enough time, a large blowout can occur, reducing the dunes to lake level over a large area. The 3 largest blowouts in the park are Beach House, Furnessville, and Big Blowout. Each extends into the interdunes, between the front rides of dunes and pockets, into the interdunal troughs. Big Blowout has uncovered an area of dead tree trunks known as the Tree Graveyard. The park also has a Youth Tent Area separate from the public campground.
