Giant, shifting mounds of sand often conjure images of the Sahara or other desert lands. But these striking landscapes are also found much closer to home. The Great Lakes basin contains the largest freshwater dune complex in the world. Approximately 275,000 acres of sand dune formations are located in Michigan alone.
How did dunes form? As glaciers retreated over thousands of years, they transported and deposited sand and sediment, which accumulated over time, creating Great Lakes dunes along the way. Sand dunes can occur whenever there is enough sand, a consistent onshore wind of at least eight miles an hour, and a place for the sand to accumulate.
Coastal dune areas, like those in the Great Lakes, are ecologically unique and support a diversity of plants and wildlife. Primary dune plants like marram grass, beach pea and sand cherry are particularly important to the health of Great Lakes dunes, as they help to anchor blowing sands.
There are several different types of sand dune formations in the Great Lakes basin. Some of these include perched dunes, linear dunes, and parabolic dunes. In Michigan, dramatic examples of each can be found along the shores of Lake Michigan and Lake Superior.
For more technical information on sand dunes and their formation: Michigan DEQ guide to sand dunes
For more information on visiting the dunes, See: www.michigan.org