Skip to main content

Lake Michigan


Lake Michigan was formed by the movement of glaciers. It is the third largest Great Lake and the sixth largest freshwater lake in the world. Its coastal areas have bays, beaches and dunes. Lake Michigan is oligotrophic, which is an unproductive type of lake with little species diversity but plenty of oxygen and clear water.

What Lives Here?

Organisms may be found throughout, on top of and along the edges of Lake Michigan. Bottom dwellers are called benthic organisms and include crayfishes and mussels. Free-swimming organisms, like fishes, are nekton. Plankton are tiny, free-floating organisms. Neuston, such as water striders, live on the surface film of water. Migrating birds use the lakeshore as a place to rest and obtain food.


boating, diving, fishing, swimming, wildlife observation and/or photography

Where is it Found?

Lake Michigan is bordered in Illinois by Lake and Cook counties, accounting for 63 Illinois shoreline miles.