There are 18 National Natural Landmark sites located within the state of Illinois. Natural features represented include large river and small stream valley ecosystems, diverse glacial landforms, and remnants of forest and prairie communities that once dominated the Illinois landscape. The sites in Illinois received NNL designation between 1965 and 1987. The sites range in size from 53 acres to over 6,500 acres and are owned by a variety of landowners including the U.S. Forest Service, Illinois Department of Natural Resources, the University of Illinois, County Forest Preserve Districts, The Nature Conservancy and private individuals.
Below is a map of sites in Illinois.
Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.