Lake Michigan History
The foundation for Lake Michigan is believed to be set about 3 billion years ago during the Precambrian Era. This was a time
of great volcanic activity and movement.
About 600 million years ago, the Paleozoic Era arrived and most of North America flooded again and again by ancient marine
seas. Many types of corals, crinoids, brachiopods, and mollusks lived in these ancient seas. The seas deposited lime, clay,
sand, and salt which eventually consolidated into limestone, shoals, sandstone, halite and gypsum which are being mined
The last time period before present day is the Pleistocene Epoch, also known as the Great Ice Age, beginning about 1 million
years ago and lasting until about 10,000 years ago. During this time, glaciers repeatedly advanced over the Great Lakes
region from the north. As they inched forward, the glaciers, up to 2,000 meters or 6,500 feet thick, scoured the land.
As the glaciers receded, large amounts of water melted in front of the ice. These glacier lakes were much larger than the
present Great Lakes. As the glaciers continued to melt, the land began to rise. This phenomenon, called uplift, continues
today which suggests that Lake Michigan as well as the other Great Lakes will continue to change.
Lake Michigan Ecology
The Straits of Mackinac, Lake Michigan's only natural outlet, connects the lake with Lake Huron to the northeast;
the Illinois Waterway links Lake Michigan with the Mississippi River and Gulf of Mexico. The Saint Lawrence Seaway has
opened Lake Michigan to international trade.
Many islands are found in the northern part of lake michigan; the northern shorelines are indented, with Green Bay and Grand
Traverse Bay the largest bays of Lake Michigan.
The Muskegon, Grand, Kalamazoo, Fox, and Menominee are the chief rivers flowing into Lake Michigan. The Chicago River
formerly flowed into the lake, but its course was reversed in 1900.
Sand dunes border the eastern and southern shores of lake michigan; Indiana Dunes National Lakeshore is along the Lake
Michigan coast in Indiana and Sleeping Bear Dunes National Lakeshore is located along the Lake Michigan coast in the northern
portion of Michigan's lower peninsula. The dunes along Lake Michigan form the longest assemblage of freshwater dunes in the
world. Learn more...visit
The forested northern region of Lake Michigan is generally sparsely populated. The southern portion, located near the heart of
the Midwest, is industrially important; the Gary-Chicago-Milwaukee urbanized area extends along the southwestern shore.
Michigan City, Gary, Chicago, Racine, Milwaukee, and Escanaba are the major lakeside cities.
Prevailing westerly winds tempered by the lake give the eastern shore a moderate climate, making it a rich fruit belt and
popular resort area. The southern part of the lake does not freeze over in the winter, but storms and ice halt interlake
movement from December to April.
Lake Michigan People
About 10,000 to 14,000 years ago, at the end of the Great Ice Age, ancient peoples traveled over extinct land bridges to what
is now the Great Lakes region. The first recorded culture, the Paleo-Indian hunted the great mastodon with a handmade chipped
stone spearhead known as a Clovis point. Evidence exists of other cultures in the region using stone for weapons through the
millennia including the Aqua-Plano and the Boreal Archaic. At about 5,000 B.C., inhabitants discovered and began to use copper
for hunting, in religious practices, and ornamentation.
The Old Copper Culture left many clues to their existence such as hundreds of copper mine pits on Isle Royale in northern
Lake Superior. Considered a very culturally advanced society, they buried their dead in cemeteries, domesticated the dog, and
were practicing simple agricultural methods. It is believed that they invented the birchbark canoe and they were the first and
most extensive users of metal anywhere in the world.
During this time, the Great Lakes were still forming, and the geology of Lake Michigan was vastly different than it is today.
For example, the straits of Mackinac was not the headwaters of Lake Michigan and Huron as we see today. The strait consisted
of a huge 300-foot canyon with a river running through it. Old Copper Indians hunted deer in the canyon below what is now the
water filled area that the Mackinac Bridge covers. These Indians also traveled through ancient forests, with the remnants now
resting below the water in the southern end of Lake Michigan. About 1,500 B.E., the Old Copper Indians began to give way to
the Woodland Indians.
For the next 2,100 years, Woodland Indians perfected the art of agriculture by using crop rotation and fertilization. They
cultivated a variety of crops including corn, squash, beans and tobacco. They traveled extensively and settled all across the
region. Individual tribes did not seem to have territorial boundaries, but were working to unite under the Iroquois Federation
when in 1615, the first documentation of the white man's arrival to the Great Lakes occurred.
Samuel de Champlain was looking for a passage west to the Pacific Ocean as a short cut to the orient. With the Huron Indians
as his guide, he traveled through the present day Lake Nipissing and the French River and finally arrived at Lake Huron. It
was not the Pacific Ocean that he had discovered, but a sweet water sea. He returned to Montreal and later sent his guide, Eitenne
Brule, to chart more of the area. After several years Brule returned to Montreal with tales of an even greater sweet water
sea (Lake Superior) and the straits of Mackinac which opened up to another vast expanse of water.
Jean Nicolet was sent to scout the area in 1634. He crossed Lake Michigan through the straights of Mackinac and landed not in
the Orient, but in Wisconsin and thus Lake Michigan was "discovered".
Lake Michigan Industry & Pollution
Despite Lake Michigan's large size, it is still sensitive to the effects of a wide range of pollutants.
Sources of pollution include:
- Runoff of soils and chemicals from agricultural lands, waste from cities, discharges from industrial areas, and leachate
from disposal sites.
- Atmospheric pollutants that fall with rain or snow into the lake.
- Direct discharge from sewage overflows.
The information shown above is courtesy of LakeMichigan.org
For complete and up to date information on Lake Michigan, please visit, the most valuable site: