Indiana Dunes National Lakeshore
The Indiana Dunes, of which the Indiana Dunes National Lakeshore (IDNL) preserves a part, are a relatively recent product of sand deposition, wave erosion, and wind erosion on the southern tip of Lake Michigan. During the warming process that ended the last Ice Age, the lake at several periods rose to levels much higher than the current lake level and laid down sandy shorelines and beaches at points that are now inland from the current coastline. Today's lake waves and currents continue to bring more sand ashore from beds underneath the surface of the current lake. This sand, further sculpted by wind and foot erosion, has become today's Indiana Dunes.
Flora and fauna
As of January 1, 2006, the admission fee for entering the Indiana Dunes State Park section of the National Lakeshore is $10.00 per motor vehicle. The fee covers the driver and passengers, and there is a discount for motor vehicles with Indiana license plates.
Most inland sections of the Indiana Dunes National Lakeshore can be visited year-round without an admission fee. Parking fees may be charged during seasonal festivals.