The shoreline of the Great Lakes is shared with Canada, Michigan, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The physical characteristics of the Great lakes shore range from high bluffs of clay and shale and rock, through lower rocky shores and sandy beaches, to low, marshy clay flats. The Great Lakes shoreline represents a unique natural resource, rich in aesthetic and ecological values, and their scenic attractiveness, many beaches and access to large water areas provide outstanding recreational opportunities. The shorelands are subject to unique problems of flooding and erosion when subject to unusually high lake levels and storms. Erosion and flooding problems are caused primarily by the forces of nature which include storms, lake level changes, wave action, frost and ice action, underground water seepage and surface water runoff.
Major storms create the largest long term changes in the shore.
Seasonal fluctuations average from about one foot to 1.5 feet.