Lake Michigan Facts

From the wave-washed beaches of the northern shore to the bustling urban-industrial communities at the southern rim, Lake Michigan represents an ecologically, culturally, and economically diverse system unparalleled in the Midwest.

Lake Michigan, by volume, is the second largest Great Lake and the only one located totally within the United States. The northern part is in the colder less developed upper Great Lakes region. It is sparsely populated, except for the Fox River Valley, and is primarily covered with mixed wood forest. The more temperate southern basin of Lake Michigan is the most urbanized area in the Great Lakes system; it contains the Milwaukee and Chicago metropolitan areas. Southern-soils are typically fertile and amenable to agriculture.

What is the Lake Michigan Basin?

The Lake Michigan basin is the area of land where rivers and streams all drain into Lake Michigan. The Lake's drainage basin covers more than 45,000 Square rules and drains parts of four states Wisconsin, Illinois, Indiana, and Michigan.

Lake Michigan discharges into Lake Huron through the Straits of Mackinac at a rate that allows for a complete change of water about every 100 years. The Lake forms a link in a waterway system that reaches east to the Atlantic Ocean and south through the Mississippi River to the Gulf of Mexico Among the large rivers that enter the Lake are the Fox and the Menominee in northeast Wisconsin, the St. Joseph, the Kalamazoo, and the Grand in southwest Michigan.

Size Statistics
Length: 307 miles
Width: 118 miles
  • 925 feet maximum depth
  • 279 feet average depth
Shoreline: 1,660 miles largely of sand & pebble beaches

Resources of the Lake Michigan Basin

Lake Michigan has unique conditions that support a wealth of biological diversity, including many plant and animal species found nowhere else in the world. Lake Michigan basin's sand dunes, coastal marshes, tall grass prairies, savannas, forests, and fens all provide essential habitats for this diversity of life. Agricultural and industrial products such as iron ore, coal, limestone, metals, petroleum, coke, and chemicals are derived from the basin's resources. The water of Lake Michigan serves many purposes. It supports large commercial and sport fishing industries. It provides industrial process and cooling water, and water for agricultural irrigation. Fleets of freighters pass over the Lake carrying bulk commerce items. Lake Michigan serves as a source of drinking water, as a place for swimming and fishing, as a scenic wonderland, and as a sink for municipal and industrial waste and runoff from the surrounding lands.

Land Usage Statistics
Land Use Basin Land Percentage Shoreline Percentage
Agricultural 44% 20%
Residential 9% 39%
Forest 41% n/a
Recreational n/a 24%
Commercial n/a 5%
Other 6% 5%

Managing the Lake Michigan Basin

While parts of the Lake Michigan ecosystem (the interacting complex of living organisms and their non-living environment) have been changed to better suit the needs of humans, the unexpected consequences of many of the changes have only recently become apparent. People have begun to realize that changes to one part of an ecosystem impact the health of the entire system. In order to improve environmental quality, all aspects of an ecosystem need to be addressed.

Managing the Lake Michigan basin as an ecosystem is an approach that takes broad systemic view of the interaction among physical, chemical, and biological components in the basin. It is a geographically comprehensive approach, covering the entire system including land, air, and water. New emphasis on the importance of atmospheric inputs of pollutants and the effects of land uses on water quality are evidence of the broad scope of management planning required in an ecosystem approach. An ecosystem approach to managing the basin includes humans as a major factor in the well-being of the system. This suggests recognition of social, economic, technical, and political variables that affect how humans use natural resources. Human culture, changing lifestyles, and attitudes must be considered in an ecosystem approach because of their effects on the integrity of the ecosystem.

Use of the Lake Michigan basin's resources has brought wealth and well-being to its residents, but the full price of the concentration of industry and people is only now being understood. The overall health of the Lake Michigan ecosystem has been degraded by human activities, and continues to be diminished. Fortunately, many people around the basin recognize the importance of restoring and protecting this resource, and are working together to formulate creative solutions to preserve intact ecosystems, restore damaged ecosystems, and repair highly disturbed areas.

Portions of the above text were adapted from EPA's Lake Michigan website:

News Feed

Love Lake Michigan

The Lake Michigan Forum has launched a public awareness campaign called Love Lake Michigan.

Call for Abstracts and Poster Presentations

The 8th biennial State of Lake Michigan and 13th annual Great Lakes Beach Association Conference are now accepting abstracts for consideration.

Great Lakes lawmakers consider statewide bans on pavement sealants

Legislators in at least three Great Lakes states are proposing statewide bans of certain pavement sealants that have killed aquatic animals and are considered a possible health risk to humans.

Office of the Great Lakes has released the 2012 Michigan Water Conservation and Efficiency Program Review

The Office of the Great Lakes has released the 2012 Michigan Water Conservation and Efficiency Program Review, which assesses Michigan’s progress in meeting its obligations under the Great Lakes–St. Lawrence River Basin Water Resources Compact.

Focus Area 2 Aquatic Pathways Summary Report

Army Corps releases Focus Area 2 Aquatic Pathways Summary Report, solicits public comment