 Wherever the beach is sandy, dunes are in process of formation, from the head of the lake in northwestern Indiana along the entire eastern shore of Lake Michigan to the Straits of Mackinac.The longest uninterrupted stretches are between the mouths of Kalamazoo and White rivers in Michigan and from the vicinity of St. Joseph, Michigan, southwestward past Michigan City, Indiana, to the head of the lake.Very prominent dunes occupy much of the interval between Ludington and Manistee, and a prominent dune belt about long in northwestern Oceana and southwestern Mason counties extends several miles each way from Pentwater.