171-466: Lake Michigan ( / ˈ m ɪ ʃ ɪ ɡ ən / MISH -ig-ən ) is one of the five Great Lakes of North America . It is the second-largest of the Great Lakes by volume (1,180 cu mi (4,900 km)) and depth (923 ft (281 m)) after Lake Superior and the third-largest by surface area (22,405 sq mi (58,030 km)), after Lake Superior and Lake Huron . To
342-511: A coastline is impossible to measure exactly . Canada borders approximately 5,200 miles (8,400 km) of coastline, while the remaining 5,300 miles (8,500 km) are bordered by the United States. Michigan has the longest shoreline of the United States, bordering roughly 3,288 miles (5,292 km) of lakes, followed by Wisconsin (820 miles (1,320 km)), New York (473 miles (761 km)), and Ohio (312 miles (502 km)). Traversing
513-707: A designated scenic road system, connects all of the Great Lakes and the St. Lawrence River. The lake is a great place to view ice volcanoes, which typically occur at the start of the winter season. Great Lakes The Great Lakes ( French : Grands Lacs ), also called the Great Lakes of North America , are a series of large interconnected freshwater lakes spanning the Canada–United States border . The five lakes are Superior , Michigan , Huron , Erie , and Ontario . (Hydrologically, Michigan and Huron are
684-542: A large mound of sand spanning the width of the river 55 feet below the surface, allowing fresh water and large cargo ships to pass over. Fresh river water flowing from the Mississippi into the Gulf of Mexico does not mix into the salt water immediately. The images from NASA 's MODIS show a large plume of fresh water, which appears as a dark ribbon against the lighter-blue surrounding waters. These images demonstrate that
855-533: A large watershed via many rivers and contain approximately 35,000 islands. There are also several thousand smaller lakes, often called "inland lakes", within the basin. The surface area of the five primary lakes combined is roughly equal to the size of the United Kingdom, while the surface area of the entire basin (the lakes and the land they drain) is about the size of the UK and France combined. Lake Michigan
1026-734: A length of 3,710 miles (5,971 km), making it the fourth longest river in the world after the Nile , Amazon , and Yangtze . When measured by the largest stream source (by water volume), the Ohio River , by extension the Allegheny River , would be the source, and the Mississippi would begin in Pennsylvania . At its source at Lake Itasca , the Mississippi River is about 3 feet (0.91 m) deep. The average depth of
1197-608: A line of waterways leading from the Saint Lawrence River to the Mississippi River and thence to the Gulf of Mexico . French coureurs des bois and voyageurs established small ports and trading communities, such as Green Bay, on the lake during the late 17th and early 18th centuries. In the 19th century, Lake Michigan was integral to the development of Chicago and the Midwestern United States west of
1368-405: A national basis. The total surface area of the lakes is approximately 94,250 square miles (244,100 km )—nearly the same size as the United Kingdom, and larger than the U.S. states of New York , New Jersey , Connecticut , Rhode Island , Massachusetts , Vermont , and New Hampshire combined. The Great Lakes coast measures approximately 10,500 miles (16,900 km), but the length of
1539-478: A natural process known as avulsion or delta switching, the lower Mississippi River has shifted its final course to the mouth of the Gulf of Mexico every thousand years or so. This occurs because the deposits of silt and sediment begin to clog its channel, raising the river's level and causing it to eventually find a steeper, more direct route to the Gulf of Mexico. The abandoned distributaries diminish in volume and form what are known as bayous . This process has, over
1710-456: A nuisance to industries by clogging pipes. The U.S. Fish and Wildlife Service estimated in 2007 that the economic impact of the zebra mussel could be about $ 5 billion over the next decade. The alewife first entered the system west of Lake Ontario via 19th-century canals. By the 1960s, the small silver fish had become a familiar nuisance to beach goers across Lakes Michigan, Huron, and Erie. Periodic mass die-offs result in vast numbers of
1881-466: A point between Milwaukee and Racine to a point between Grand Haven and Muskegon, divides the lake into northern and southern basins. Each basin has a clockwise flow of water, deriving from rivers and winds. Prevailing westerly winds tend to move the surface water toward the east, producing a moderating effect on the climate of western Michigan. There is a mean difference in summer water temperatures of 5 to 10 degrees Fahrenheit (2 to 5 degrees Celsius) between
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#17327646386432052-681: A possible reason for a decrease in population of various whitefish , important because of their culinary desirability and, hence, economic consequence. Moreover, between 1879 and 1899, reported whitefish harvests declined from some 24.3 million pounds (11 million kg) to just over 9 million pounds (4 million kg). By 1900, commercial fishermen on Lake Michigan were hauling in an average of 41 million pounds of fish annually. By 1938, Wisconsin's commercial fishing operations were motorized and mechanized, generating jobs for more than 2,000 workers, and hauling 14 million pounds per year. The population of giant freshwater mussels
2223-560: A relatively small area of southeast Lake Michigan where savanna or prairie occasionally intruded). Logging, urbanization, and agriculture uses have changed that relationship. In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron 68%, Lake Ontario 49%, Lake Michigan 41%, and Lake Erie, where logging and urbanization has been most extensive, 21%. Some of these forests are second or third growth (i.e. they have been logged before, changing their composition). At least 13 wildlife species are documented as becoming extinct since
2394-498: A result of improvements to the Welland Canal in 1918, an invasion of sea lampreys and overharvesting , there has been a decline in native lake trout populations, ultimately causing an increase in the population of another invasive species, the alewife . As a result, salmonids, including various strains of brown trout , steelhead ( rainbow trout ), coho and chinook salmon , were introduced as predators in order to decrease
2565-527: A row in 2020. Lake levels tend to be the lowest in winter. The normal low-water mark is 1.00 foot (30 cm) below datum ( 577.5 ft or 176.0 m ). In the winter of 1964, Lakes Michigan and Huron reached their lowest level at 1.38 feet (42 cm) below datum. As with the high-water records, monthly low-water records were set each month from February 1964 through January 1965. During this twelve-month period, water levels ranged from 1.38 to 0.71 feet (42–22 cm) below Chart Datum. The all-time low-water mark
2736-489: A season, and can survive poor water quality conditions. The influx of parasitic lamprey populations after the development of the Erie Canal and the much later Welland Canal led to the two federal governments of the United States and Canada working on joint proposals to control it. By the mid-1950s, the lake trout populations of Lakes Michigan and Huron were reduced, with the lamprey deemed largely to blame. This led to
2907-746: A second fault line, the Saint Lawrence rift , formed approximately 570 million years ago, the basis for Lakes Ontario and Erie was created, along with what would become the Saint Lawrence River. The Great Lakes are estimated to have been formed at the end of the Last Glacial Period (the Wisconsin glaciation ended 10,000 to 12,000 years ago), when the Laurentide Ice Sheet receded. The retreat of
3078-641: A single body of water, as they are joined by Straits of Mackinac .) The Great Lakes Waterway enables modern travel and shipping by water among the lakes. The lakes connect to the Atlantic Ocean via the Saint Lawrence River , and to the Mississippi River basin through the Illinois Waterway . The Great Lakes are the largest group of freshwater lakes on Earth by total area and the second-largest by total volume. They contain 21% of
3249-581: A small percid fish from Eurasia, became the most abundant fish species in Lake Superior's Saint Louis River within five years of its detection in 1986. Its range, which has expanded to Lake Huron, poses a significant threat to the lower lake fishery. Five years after first being observed in the St. Clair River, the round goby can now be found in all of the Great Lakes. The goby is considered undesirable for several reasons: it preys upon bottom-feeding fish, overruns optimal habitat, spawns multiple times
3420-476: A vital transportation artery and communications link. In the 19th century, during the height of the ideology of manifest destiny , the Mississippi and several tributaries, most notably its largest, the Ohio and Missouri , formed pathways for the western expansion of the United States. The river also became the subject of American literature , particularly in the writings of Mark Twain . Formed from thick layers of
3591-414: Is "new" water, originating from rivers, precipitation, and groundwater springs. In the post-glacial period, evaporation , and drainage have generally been balanced, making the levels of the lakes relatively constant. Intensive human population growth began in the region in the 20th century and continues today. At least two human water use activities have been identified as having the potential to affect
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#17327646386433762-794: Is 208,200 cu ft/s (5,900 m /s). Thus, by volume, the main branch of the Mississippi River system at Cairo can be considered to be the Ohio River (and the Allegheny River further upstream), rather than the Middle Mississippi. In addition to the Ohio River , the major tributaries of the Lower Mississippi River are the White River , flowing in at the White River National Wildlife Refuge in east-central Arkansas;
3933-427: Is 46 fathoms 3 feet (279 ft; 85 m), while its greatest depth is 153 fathoms 5 feet (923 ft; 281 m). It contains a volume of 1,183 cubic miles (4,932 km) of water. Green Bay in the northwest is its largest bay. Grand Traverse Bay in its northeast is another large bay. Lake Michigan's deepest region, which lies in its northern half, is called Chippewa Basin (named after prehistoric Lake Chippewa ) and
4104-575: Is a meandering river in a broad, flat area, only rarely flowing alongside a bluff (as at Vicksburg, Mississippi ). The Mississippi River is known as the Middle Mississippi from the Upper Mississippi River's confluence with the Missouri River at St. Louis, Missouri , for 190 miles (310 km) to its confluence with the Ohio River at Cairo, Illinois . The Middle Mississippi is relatively free-flowing. From St. Louis to
4275-498: Is called the Lower Mississippi River from its confluence with the Ohio River to its mouth at the Gulf of Mexico, a distance of about 1,000 miles (1,600 km). At the confluence of the Ohio and the Middle Mississippi, the long-term mean discharge of the Ohio at Cairo, Illinois is 281,500 cubic feet per second (7,970 cubic meters per second), while the long-term mean discharge of the Mississippi at Thebes, Illinois (just upriver from Cairo)
4446-912: Is controlled and managed as a series of pools created by 26 locks and dams. The Upper Mississippi River is joined by the Minnesota River at Fort Snelling in the Twin Cities ; the St. Croix River near Prescott, Wisconsin ; the Cannon River near Red Wing, Minnesota ; the Zumbro River at Wabasha, Minnesota ; the Black , La Crosse , and Root rivers in La Crosse, Wisconsin ; the Wisconsin River at Prairie du Chien, Wisconsin ;
4617-734: Is controlled by the locks operated by the bi-national Lake Superior Board of Control . Lake Michigan is the only Great Lake that is wholly within the borders of the United States; the others are shared with Canada. Lake Michigan has a surface area of 22,404 sq mi (58,030 km); (13,237 square miles (34,280 km) lying in Michigan, 7,358 square miles (19,060 km) in Wisconsin, 234 square miles (610 km) in Indiana, & 1,576 square miles (4,080 km) in Illinois) making it
4788-546: Is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km ), of which only about one percent is in Canada. The Mississippi ranks as the world's tenth-largest river by discharge flow, and the largest in North America. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Many were hunter-gatherers , but some, such as
4959-633: Is flat according to the International Joint Commission. Reports about this issue on the U.S. side highlight five large municipal systems (those of Detroit, Cleveland, Buffalo, Milwaukee and Gary ) as being the largest current periodic sources of untreated discharges into the Great Lakes. The fish of the Great Lakes have anti-depressant drugs meant for humans in their brains, which has caused concerns. The number of American adults who take anti-depressant drugs rose from 7.7% of all American adults in 1999–2002 to 12.7% in 2011–2014. As
5130-557: Is heavy. Pleasure boats can enter or exit the Great Lakes by way of the Erie Canal and Hudson River in New York. The Erie Canal connects to the Great Lakes at the east end of Lake Erie (at Buffalo, New York ) and at the south side of Lake Ontario (at Oswego, New York ). The lakes were originally fed by both precipitation and meltwater from glaciers which are no longer present. In modern times, only about 1% of volume per year
5301-472: Is largely a multi-thread stream with many bars and islands. From its confluence with the St. Croix River downstream to Dubuque, Iowa , the river is entrenched, with high bedrock bluffs lying on either side. The height of these bluffs decreases to the south of Dubuque, though they are still significant through Savanna, Illinois . This topography contrasts strongly with the Lower Mississippi, which
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5472-562: Is separated from South Chippewa Basin by a relatively shallower area called the Mid Lake Plateau. In the mid 20th century, construction of the Saint Lawrence Seaway and Great Lakes Waterway opened the Great Lakes to ocean-going vessels. But the wider ocean-going container ships that were developed later do not fit through the locks on these routes, which limits shipping on the lakes. Lake freighters are used on
5643-484: Is supported by tourism , with large seasonal populations attracted by Lake Michigan. Many seasonal residents have summer homes along the waterfront and return to other homes for the winter. The southern tip of the lake near Gary, Indiana, is heavily industrialized. Cities on the shores of Lake Michigan include: Illinois Indiana Michigan Wisconsin The National Park Service maintains
5814-515: Is the only one of the Great Lakes that is entirely within the United States; the others form a water boundary between the United States and Canada. The lakes are divided among the jurisdictions of the Canadian province of Ontario and the U.S. states of Michigan , Wisconsin , Minnesota , Illinois , Indiana , Ohio , Pennsylvania , and New York . Both the province of Ontario and the state of Michigan include in their boundaries portions of four of
5985-539: Is the only true waterfall on the entire Mississippi River. The water elevation continues to drop steeply as it passes through the gorge carved by the waterfall. After the completion of the St. Anthony Falls Lock and Dam in 1963, the river's head of navigation moved upstream, to the Coon Rapids Dam . However, the Locks were closed in 2015 to control the spread of invasive Asian carp , making Minneapolis once again
6156-453: Is the world's largest lake , by area, located fully in one country, and is shared, from west to east, by the U.S. states of Wisconsin , Illinois , Indiana , and Michigan . Ports along its shores include Chicago , Illinois, Gary , Indiana, Milwaukee and Green Bay , Wisconsin, and Muskegon , Michigan. To the north, the lake is flanked by long bays , including Green Bay in the northwest, and Grand Traverse and Little Traverse bays in
6327-880: The Arkansas River , joining the Mississippi at Arkansas Post ; the Big Black River in Mississippi; and the Yazoo River , meeting the Mississippi at Vicksburg, Mississippi . Deliberate water diversion at the Old River Control Structure in Louisiana allows the Atchafalaya River in Louisiana to be a major distributary of the Mississippi River, with 30% of the combined flow of the Mississippi and Red Rivers flowing to
6498-599: The Chicago Lakefront Trail . Where there are no beaches or marinas, stone or concrete revetments protect the shoreline from erosion. The Chicago lakefront is accessible for about 24 miles (39 km) between the city's southern and northern limits along the lake. Twelve million people live along Lake Michigan's shores, mainly in the Chicago and Milwaukee metropolitan areas. The economy of many communities in northern Michigan and Door County, Wisconsin ,
6669-765: The Chicago Sanitary and Ship Canal to the Gulf of Mexico via the Illinois River (from the Chicago River ) and the Mississippi River. An alternate track is via the Illinois River (from Chicago), to the Mississippi, up the Ohio, and then through the Tennessee–Tombigbee Waterway (a combination of a series of rivers and lakes and canals), to Mobile Bay and the Gulf of Mexico. Commercial tug -and- barge traffic on these waterways
6840-539: The Conference of Great Lakes and St. Lawrence Governors and Premiers , intergovernmental organization led by the governing chief executives of the Canadian provinces of Ontario and Québec , and by the governors of the U.S. states of Illinois , Indiana , Michigan , Minnesota , New York , Ohio , Pennsylvania , and Wisconsin . The Conference came into force, in December 2008, with the enactment of laws in all of
7011-820: The Door Peninsula , the Peninsulas of Michigan , and the Ontario Peninsula . Some of these peninsulas even contain smaller peninsulas, such as the Bruce , Keweenaw , Leelanau , Niagara , and Thumb peninsulas. Population centers on the peninsulas include Grand Rapids , Flint , and Detroit in Michigan along with London , Hamilton , Brantford , and Toronto in Ontario. Although the Saint Lawrence Seaway and Great Lakes Waterway make
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7182-529: The Environmental Protection Agency have shown that when the mercury comes in contact with many of the bacteria and compounds in the fresh water, it forms the compound methyl mercury , which has a much greater impact on human health than elemental mercury due to a higher propensity for absorption. This form of mercury is not detrimental to a majority of fish types, but is very detrimental to people and other wildlife animals who consume
7353-690: The Finger Lakes region of New York, as well as in Prince Edward County, Ontario , on Lake Ontario's northeast shore. The Great Lakes have been observed to help intensify storms, such as Hurricane Hazel in 1954, and the 2011 Goderich, Ontario tornado , which moved onshore as a tornadic waterspout . In 1996, a rare tropical or subtropical storm was observed forming in Lake Huron, dubbed the 1996 Lake Huron cyclone . Rather large severe thunderstorms covering wide areas are well known in
7524-478: The Fox River , nearly to its headwaters , in their search for the Mississippi River . By the late 18th century, the eastern portions of the straits were controlled by Fort Mackinac on Mackinac Island , a British colonial and early American military base and fur trade center, founded in 1781. With the advent of European exploration into the area in the late 17th century, Lake Michigan became used as part of
7695-527: The Gulf of Mexico , part of the Atlantic Ocean. The total catchment of the Mississippi River covers nearly 40% of the landmass of the continental United States. The highest point within the watershed is also the highest point of the Rocky Mountains , Mount Elbert at 14,440 feet (4,400 m). In the United States, the Mississippi River drains the majority of the area between the crest of
7866-603: The Minnesota River , James River , and Milk River valleys. When the ice sheet completely retreated, many of these "temporary" rivers found paths to Hudson Bay or the Arctic Ocean, leaving the Mississippi Basin with many features "over-sized" for the existing rivers to have carved in the same time period. Ice sheets during the Illinoian Stage , about 300,000 to 132,000 years before present, blocked
8037-559: The Mississippi River Delta in the Gulf of Mexico . With its many tributaries , the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The river either borders or passes through the states of Minnesota , Wisconsin , Iowa , Illinois , Missouri , Kentucky , Tennessee , Arkansas , Mississippi , and Louisiana . The main stem
8208-466: The Mound Builders , formed prolific agricultural and urban civilizations, and some practiced aquaculture . The arrival of Europeans in the 16th century changed the native way of life as first explorers, then settlers, ventured into the basin in increasing numbers. The river served sometimes as a barrier, forming borders for New Spain , New France , and the early United States, and throughout as
8379-521: The Niagara Escarpment precludes all natural navigation, the four upper lakes are commonly called the "upper great lakes". This designation is not universal. Those living on the shore of Lake Superior often refer to all the other lakes as "the lower lakes", because they are farther south. Sailors of bulk freighters transferring cargoes from Lake Superior and northern Lake Michigan and Lake Huron to ports on Lake Erie or Ontario commonly refer to
8550-1200: The Rock River at the Quad Cities ; the Iowa River near Wapello, Iowa ; the Skunk River south of Burlington, Iowa ; and the Des Moines River at Keokuk, Iowa . Other major tributaries of the Upper Mississippi include the Crow River in Minnesota, the Chippewa River in Wisconsin, the Maquoketa River and the Wapsipinicon River in Iowa, and the Illinois River in Illinois. The Upper Mississippi
8721-403: The Rocky Mountains and the crest of the Appalachian Mountains , except for various regions drained to Hudson Bay by the Red River of the North ; to the Atlantic Ocean by the Great Lakes and the Saint Lawrence River ; and to the Gulf of Mexico by the Rio Grande , the Alabama and Tombigbee rivers, the Chattahoochee and Appalachicola rivers, and various smaller coastal waterways along
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#17327646386438892-432: The Sleeping Bear Dunes National Lakeshore and Indiana Dunes National Park . Parts of the shoreline are within the Hiawatha National Forest and the Manistee National Forest . The Manistee National Forest section of the shoreline includes the Nordhouse Dunes Wilderness . The Lake Michigan division of the Michigan Islands National Wildlife Refuge is also within the lake, as are the Green Bay National Wildlife Refuge and
9063-423: The Wisconsin Shipwreck Coast National Marine Sanctuary . There are numerous state and local parks located on the shores of the lake or on islands within the lake: Lake Michigan is home to a small variety of fish species and other organisms. It was originally home to lake whitefish , lake trout , yellow perch , panfish , largemouth bass , smallmouth bass and bowfin , as well as some species of catfish . As
9234-421: The biosphere . Since the 19th century, an estimated 160 new species have found their way into the Great Lakes ecosystem; many have become invasive; the overseas ship ballast and ship hull parasitism are causing severe economic and ecological impacts. According to the Inland Seas Education Association, on average a new species enters the Great Lakes every eight months. Introductions into the Great Lakes include
9405-429: The headwaters region and serve multiple purposes, including power generation and recreation. The remaining 29 dams, beginning in downtown Minneapolis, all contain locks and were constructed to improve commercial navigation of the upper river. Taken as a whole, these 43 dams significantly shape the geography and influence the ecology of the upper river. Beginning just below Saint Paul, Minnesota , and continuing throughout
9576-422: The most recent Ice Age . The southernmost extent of this enormous glaciation extended well into the present-day United States and Mississippi basin. When the ice sheet began to recede, hundreds of feet of rich sediment were deposited, creating the flat and fertile landscape of the Mississippi Valley. During the melt, giant glacial rivers found drainage paths into the Mississippi watershed, creating such features as
9747-414: The zebra mussel , which was first discovered in 1988, and quagga mussel in 1989. Since 2000, the invasive quagga mussel has smothered the bottom of Lake Michigan almost from shore to shore, and their numbers are estimated at 900 trillion. The mollusks are efficient filter feeders, competing with native mussels and reducing available food and spawning grounds for fish. In addition, the mussels may be
9918-527: The " snowbelts " receive regular snow fall from this localized weather pattern, especially along the eastern shores of the lakes. Snowbelts are found in Wisconsin, Michigan, Ohio, Pennsylvania, New York, and Ontario. Related to the lake effect is the regular occurrence of fog, particularly along the shorelines of the lakes. This is most noticeable along Lake Superior's shores. The lakes tend to moderate seasonal temperatures to some degree but not with as large an influence as do large oceans; they absorb heat and cool
10089-424: The "true head" of the Mississippi River as a combination of the last four letters of the Latin word for truth ( ver itas ) and the first two letters of the Latin word for head ( ca put ). However, the lake is in turn fed by a number of smaller streams. From its origin at Lake Itasca to St. Louis, Missouri , the waterway's flow is moderated by 43 dams. Fourteen of these dams are located above Minneapolis in
10260-406: The 18th century, the river was set by the Treaty of Paris as, for the most part, the western border of the new United States. With the Louisiana Purchase and the country's westward expansion, it became a convenient boundary line between the western and eastern halves of the country. This is reflected in the Gateway Arch in St. Louis, which was designed to symbolize the opening of the West, and
10431-423: The 20th century, the Mississippi River has also experienced major pollution and environmental problems — most notably elevated nutrient and chemical levels from agricultural runoff, the primary contributor to the Gulf of Mexico dead zone . The word Mississippi itself comes from Misi zipi , the French rendering of the Anishinaabe ( Ojibwe or Algonquin ) name for the river, Misi-ziibi (Great River). In
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#173276463864310602-501: The Canadian side, Toronto , Hamilton and Mississauga . Though the five lakes lie in separate basins, they form a single, naturally interconnected body of fresh water, within the Great Lakes Basin . As a chain of lakes and rivers, they connect the east-central interior of North America to the Atlantic Ocean. From the interior to the outlet at the Saint Lawrence River, water flows from Superior to Huron and Michigan, southward to Erie, and finally northward to Lake Ontario. The lakes drain
10773-430: The Chicago Sanitary and Ship Canal in order to keep several species of invasive Asian carp out of the lakes. These fast-growing planktivorous fish have heavily colonized the Mississippi and Illinois river systems. Invasive species, particularly zebra and quagga mussels, may be at least partially responsible for the collapse of the deepwater demersal fish community in Lake Huron, as well as drastic unprecedented changes in
10944-402: The Earth's mantle (specifically, the Bermuda hotspot ) that was undergoing a period of intense activity. The upwelling of magma from the hotspot forced the further uplift to a height of perhaps 2–3 km of part of the Appalachian-Ouachita range, forming an arch that blocked southbound water flows. The uplifted land quickly eroded and, as North America moved away from the hot spot and as
11115-661: The Great Lakes Indian Fish and Wildlife Commission, which harvest 50 percent of the Great Lakes commercial catch in Michigan waters, and 45 state-licensed commercial fishing enterprises. The prime commercial species is the lake whitefish. The annual harvest declined from an average of 11 million pounds (5,000,000 kg) from 1981 through to 1999 to more recent annual harvests of 8 to 9.5 million pounds (3,600,000 to 4,300,000 kg). The price for lake whitefish dropped from $ 1.04/lb. to as low as $ 0.40/lb during periods of high production. Sports fishing includes salmon, whitefish, smelt , lake trout and walleye as major catches. In
11286-407: The Great Lakes accessible to ocean-going vessels, shifts in shipping to wider ocean-going container ships —which do not fit through the locks on these routes—have limited container shipping on the lakes. Most Great Lakes trade is of bulk material, and bulk freighters of Seawaymax -size or less can move throughout the entire lakes and out to the Atlantic. Larger ships are confined to working within
11457-621: The Great Lakes by way of the Erie Canal and Hudson River in New York. The Erie Canal connects to the Great Lakes at the east end of Lake Erie (at Buffalo, New York ) and at the south side of Lake Ontario (at Oswego, New York ). The lake fluctuates from month to month with the highest lake levels typically occurring in summer. The normal high-water mark is 2.00 feet (0.61 m) above datum ( 577.5 ft (176.0 m) ). In October 1986, Lakes Michigan and Huron reached their highest level at 5.92 feet (1.80 m) above datum. The monthly average high-water records were broken for several months in
11628-459: The Great Lakes during mid-summer; these Mesoscale convective complexes or MCCs can cause damage to wide swaths of forest and shatter glass in city buildings. These storms mainly occur during the night, and the systems sometimes have small embedded tornadoes, but more often straight-line winds accompanied by intense lightning. Historically, the Great Lakes, in addition to their lake ecology , were surrounded by various forest ecoregions (except in
11799-441: The Great Lakes each year. Plastics in the water break up into very small particles known as microplastics . Microplastics can also come from synthetic clothing washed down our drains. Plastic waste found in the lakes include single-use plastics , plastics used in packaging, takeout containers as well as pre-production pellets produced by plastics industry . High concentrations of microplastics were discovered in 100 percent of
11970-438: The Great Lakes region include: Plant lists include: Logging of the extensive forests in the Great Lakes region removed riparian and adjacent tree cover over rivers and streams, which provide shade, moderating water temperatures in fish spawning grounds. Removal of trees also destabilized the soil, with greater volumes washed into stream beds causing siltation of gravel beds, and more frequent flooding. Running cut logs down
12141-480: The Great Lakes. A number of self-operating floating devices called Seabin, were put in the Great Lakes to capture plastic trash as part of the Great Lakes Plastic Cleanup project. The project captured 74,000 pieces of trash using this technology between 2020 and 2021; however, it does not claim to catch up with 22 million pounds (10.0 kt) of plastic that ends up in Great Lakes every year. The production, consumption, and throwing away of plastics seems to remain
12312-712: The Gulf of Mexico by this route, rather than continuing down the Mississippi's current channel past Baton Rouge and New Orleans on a longer route to the Gulf. Although the Red River was once an additional tributary, its water now flows separately into the Gulf of Mexico through the Atchafalaya River. The Mississippi River has the world's fourth-largest drainage basin ("watershed" or "catchment"). The basin covers more than 1,245,000 square miles (3,220,000 km ), including all or parts of 32 U.S. states and two Canadian provinces. The drainage basin empties into
12483-495: The Gulf. The Mississippi River empties into the Gulf of Mexico about 100 miles (160 km) downstream from New Orleans. Measurements of the length of the Mississippi from Lake Itasca to the Gulf of Mexico vary somewhat, but the United States Geological Survey 's number is 2,340 miles (3,766 km). The retention time from Lake Itasca to the Gulf is typically about 90 days; while speed varies along
12654-469: The Illinoian Stage. Timeline of outflow course changes In March 1876, the Mississippi suddenly changed course near the settlement of Reverie, Tennessee , leaving a small part of Tipton County, Tennessee , attached to Arkansas and separated from the rest of Tennessee by the new river channel. Since this event was an avulsion , rather than the effect of incremental erosion and deposition,
12825-504: The Michigan state stone, can be found. The beaches of the western coast and the northernmost part of the east coast are often rocky, with some sandy beaches. The southern and eastern beaches are typically sandy and dune-covered. This is partly because of the prevailing winds from the west (which also cause thick layers of ice to build on the eastern shore in winter). The Chicago city waterfront has been developed for parks, beaches , harbors and marinas, and residential developments connected by
12996-578: The Midwestern and eastern U.S. These earthquakes created Reelfoot Lake in Tennessee from the altered landscape near the river. When measured from its traditional source at Lake Itasca , the Mississippi has a length of 2,340 miles (3,766 km). When measured from its longest stream source (most distant source from the sea), Brower's Spring in Montana , the source of the Missouri River , it has
13167-480: The Mississippi River between Saint Paul and Saint Louis is between 9 and 12 feet (2.7–3.7 m) deep, the deepest part being Lake Pepin , which averages 20–32 feet (6–10 m) deep and has a maximum depth of 60 feet (18 m). Between where the Missouri River joins the Mississippi at Saint Louis, Missouri, and Cairo, Illinois, the depth averages 30 feet (9 m). Below Cairo, where the Ohio River joins,
13338-411: The Mississippi River has experienced numerous large and small changes to its main course, as well as additions, deletions, and other changes among its numerous tributaries, and the lower Mississippi River has used different pathways as its main channel to the Gulf of Mexico across the delta region. As Pangaea began to break up about 95 million years ago, North America passed over a volcanic " hotspot " in
13509-469: The Mississippi River near New Madrid, Missouri , between Memphis and St. Louis, is related to an aulacogen (failed rift) that formed at the same time as the Gulf of Mexico. This area is still quite active seismically. Four great earthquakes in 1811 and 1812 , estimated at 8 on the Richter magnitude scale , had tremendous local effects in the then sparsely settled area, and were felt in many other places in
13680-456: The Mississippi near Rock Island, Illinois, diverting it to its present channel farther to the west, the current western border of Illinois. The Hennepin Canal roughly follows the ancient channel of the Mississippi downstream from Rock Island to Hennepin, Illinois . South of Hennepin, to Alton, Illinois , the current Illinois River follows the ancient channel used by the Mississippi River before
13851-640: The Ohio River confluence, the Middle Mississippi falls 220 feet (67 m) over 180 miles (290 km) for an average rate of 1.2 feet per mile (23 cm/km). At its confluence with the Ohio River, the Middle Mississippi is 315 feet (96 m) above sea level. Apart from the Missouri and Meramec rivers of Missouri and the Kaskaskia River of Illinois, no major tributaries enter the Middle Mississippi River. The Mississippi River
14022-542: The Ohio to the Gulf of Mexico. The Upper Mississippi runs from its headwaters to its confluence with the Missouri River at St. Louis, Missouri. It is divided into two sections: The source of the Upper Mississippi branch is traditionally accepted as Lake Itasca , 1,475 feet (450 m) above sea level in Itasca State Park in Clearwater County, Minnesota . The name Itasca was chosen to designate
14193-479: The Port District, Calumet Harbor , is maintained by the U.S. Army Corps of Engineers . Two passenger and vehicle ferries operate ferry services across Lake Michigan, both connecting Wisconsin on the western shore with Michigan on the east. From May to October, the historic steamship, SS Badger , operates daily between Manitowoc, Wisconsin, and Ludington, Michigan, connecting U.S. Highway 10 between
14364-509: The Straits of Mackinac. The straits are five miles (8 km) wide and 120 feet (37 m) deep; the water levels rise and fall together, and the flow between Michigan and Huron frequently reverses direction. Dispersed throughout the Great Lakes are approximately 35,000 islands . The largest among them is Manitoulin Island in Lake Huron, the largest island in any inland body of water in
14535-427: The U.S. A variety of steps taken to process industrial and municipal pollution discharges into the system greatly improved water quality by the 1980s, and Lake Erie in particular is significantly cleaner. Discharge of toxic substances has been sharply reduced. Federal and state regulations control substances like PCBs . The first of 43 " Great Lakes Areas of Concern " to be formally "de-listed" through successful cleanup
14706-546: The Upper Mississippi River is the Upper St. Anthony Falls Lock and Dam in Minneapolis. Above the dam, the river's elevation is 799 feet (244 m). Below the dam, the river's elevation is 750 feet (230 m). This 49-foot (15 m) drop is the largest of all the Mississippi River locks and dams. The origin of the dramatic drop is a waterfall preserved adjacent to the lock under an apron of concrete. Saint Anthony Falls
14877-604: The Upper Mississippi is a simple steel culvert, through which the river (locally named "Nicolet Creek") flows north from Lake Nicolet under "Wilderness Road" to the West Arm of Lake Itasca, within Itasca State Park . The earliest bridge across the Mississippi River was built in 1855. It spanned the river in Minneapolis where the current Hennepin Avenue Bridge is located. No highway or railroad tunnels cross under
15048-413: The Wisconsin and Michigan shores. Hydrologically Michigan and Huron are the same body of water (sometimes called Lake Michigan-Huron ) but are normally considered distinct. Counted together, it is the largest body of fresh water in the world by surface area. The Mackinac Bridge is generally considered the dividing line between them. The main inflow to Lake Michigan from Lake Superior, through Lake Huron,
15219-495: The air in summer, then slowly radiate that heat in autumn. They protect against frost during transitional weather and keep the summertime temperatures cooler than further inland. This effect can be very localized and overridden by offshore wind patterns. This temperature buffering produces areas known as " fruit belts ", where fruit can be produced that is typically grown much farther south. For instance, western Michigan has apple orchards, and cherry orchards are cultivated adjacent to
15390-459: The anti-depressant drugs pass out of human bodies and through sanitation systems into the Great Lakes, this has resulted in fish in the Great Lakes with twenty times the level of anti-depressants in their brains than what is in the water, leading to the fish being exceedingly happy and hence less risk-averse, to the extent of damaging the fish populations. Researchers have found that more than 22 million pounds (10.0 kt) of plastic end up in
15561-555: The areas drained by them. Denser salt water from the Gulf of Mexico forms a salt wedge along the river bottom near the mouth of the river, while fresh water flows near the surface. In drought years, with less fresh water to push it out, salt water can travel many miles upstream—64 miles (103 km) in 2022—contaminating drinking water supplies and requiring the use of desalination . The United States Army Corps of Engineers constructed "saltwater sills" or "underwater levees" to contain this in 1988, 1999, 2012, and 2022. This consists of
15732-432: The arrival of Europeans, and many more are threatened or endangered. Meanwhile, exotic and invasive species have also been introduced. While the organisms living on the bottom of shallow waters are similar to those found in smaller lakes, the deep waters contain organisms found only in deep, cold lakes of the northern latitudes. These include the delicate opossum shrimp (order mysida ), the deepwater scud (a crustacean of
15903-635: The basins they had carved into the land, which then filled with meltwater. The lakes have been a major source for transportation, migration, trade, and fishing, serving as a habitat to many aquatic species in a region with much biodiversity . The surrounding region is called the Great Lakes region , which includes the Great Lakes Megalopolis . Major cities within the region include, on the American side, from east to west, Buffalo , Cleveland , Detroit , Chicago , and Milwaukee ; and, on
16074-420: The bottom via submersible as part of a research expedition. The warming of Lake Michigan was the subject of a 2018 report by Purdue University . In each decade since 1980, steady increases in obscure surface temperature have occurred. This is likely to lead to decreasing native habitat and to adversely affect native species survival, including game fish. The Milwaukee Reef , running under Lake Michigan from
16245-427: The core of Great Lakes trash problem. Algae such as diatoms , along with other phytoplankton , are photosynthetic primary producers supporting the food web of the Great Lakes, and have been affected by global warming . The changes in the size or in the function of the primary producers may have a direct or an indirect impact on the food web. Photosynthesis carried out by diatoms constitutes about one fifth of
16416-427: The course of the river, this gives an overall average of around 26 mi (42 km) per day, or 1 mi (1.6 km) per hour. The stream gradient of the entire river is 0.01%, a drop of 450 m over 3,766 km. The Mississippi River discharges at an annual average rate of between 200 and 700 thousand cubic feet per second (6,000 and 20,000 m /s). The Mississippi is the fourteenth largest river in
16587-779: The cyanobacteria ... will produce toxins", said Michael McKay, of the University of Windsor. Water quality testing was underway in August 2019. Until 1970, mercury was not listed as a harmful chemical, according to the United States Federal Water Quality Administration. In the 21st century, mercury has become more apparent in water tests. Mercury compounds have been used in paper mills to prevent slime from forming during their production, and chemical companies have used mercury to separate chlorine from brine solutions. Studies conducted by
16758-403: The delta of the Chippewa River of Wisconsin as it enters the Upper Mississippi, is more than 2 miles (3.2 km) wide. By the time the Upper Mississippi reaches Saint Paul , Minnesota, below Lock and Dam No. 1, it has dropped more than half its original elevation and is 687 feet (209 m) above sea level. From St. Paul to St. Louis, Missouri, the river elevation falls much more slowly and
16929-592: The depth averages 50–100 feet (15–30 m) deep. The deepest part of the river is in New Orleans, where it reaches 200 feet (61 m) deep. The Mississippi River runs through or along 10 states, from Minnesota to Louisiana , and is used to define portions of these states' borders, with Wisconsin , Illinois , Kentucky , Tennessee , and Mississippi along the east side of the river, and Iowa , Missouri , and Arkansas along its west side. Substantial parts of both Minnesota and Louisiana are on either side of
17100-653: The earliest European maps of the region, the name of Lake Illinois has been found (named for the Illinois Confederation of tribes), in addition to that of "Michigan". During the 1640s and 1650s, the Beaver Wars (over the fur trade with the European colonies), initiated by the Iroquois , forced a massive demographic-shift, as their western neighbors fled the violence. The Iroquois sought refuge to
17271-501: The early 17th century, when Western European explorers made their first forays into the region, they encountered descendants of the Late Woodland Native Americans, mainly the historic Chippewa , Menominee , Sauk , Fox , Winnebago , Miami , Ottawa and Potawatomi peoples. The French explorer Jean Nicolet is believed to have been the first European to reach Lake Michigan, possibly in 1634 or 1638. In
17442-413: The east, its basin is conjoined with that of Lake Huron through the wide and deep Straits of Mackinac , giving it the same surface elevation as its easterly counterpart; geologically, the two bodies are a single lake that is, by area, the largest freshwater lake in the world. Lake Michigan is the only Great Lake located fully in the United States; the other four are shared between the U.S. and Canada. It
17613-461: The fish that were studied by researchers from the Rochman Lab. About 50 million pounds (23 kt) of fish is harvested each year from Great Lakes which has raised concerns on how this might affect human health. Microscopic pieces of plastic have also been found in drinking water coming from Great Lakes. It is estimated that nearly 40 million people in the region rely on drinking water from
17784-443: The fish washing up on shore; estimates by various governments have placed the percentage of Lake Michigan's biomass which was made up of alewives in the early 1960s as high as 90%. In the late 1960s, the various state and federal governments began stocking several species of salmonids, including the native lake trout as well as non-native chinook and coho salmon; by the 1980s, alewife populations had dropped drastically. The ruffe ,
17955-443: The fish. Mercury has been known for health related problems such as birth defects in humans and animals, and the near extinction of eagles in the Great Lakes region. The amount of raw sewage dumped into the waters was the primary focus of both the first Great Lakes Water Quality Agreement and federal laws passed in both countries during the 1970s. Implementation of secondary treatment of municipal sewage by major cities greatly reduced
18126-471: The five Great Lakes have long been called inland seas . Depending on how it is measured, by surface area, either Lake Superior or Lake Michigan–Huron is the second-largest lake in the world and the largest freshwater lake. Lake Michigan is the largest lake, by surface area, that is entirely within one country, the United States. The Great Lakes began to form at the end of the Last Glacial Period around 14,000 years ago, as retreating ice sheets exposed
18297-495: The focus on the " Trans-Mississippi " region in the Trans-Mississippi Exposition . Regional landmarks are often classified in relation to the river, such as "the highest peak east of the Mississippi " or "the oldest city west of the Mississippi". The FCC also uses it as the dividing line for broadcast call-signs , which begin with W to the east and K to the west, overlapping in media markets along
18468-417: The glaciers "rebounded" as it was uncovered. Since the glaciers covered some areas longer than others, this glacial rebound occurred at different rates. The Great Lakes have a humid continental climate, Köppen climate classification Dfa (in southern areas) and Dfb (in northern parts) with varying influences from air masses from other regions including dry, cold Arctic systems, mild Pacific air masses from
18639-410: The historical average level. Although "true tides—changes in water level caused by the gravitational forces of the sun and moon—do occur in a semi-diurnal (twice daily) pattern", such changes are quite small and generally obscured by other forces. The lake levels are affected primarily by changes in regional meteorology and climatology. The outflows from Lakes Superior and Ontario are regulated, while
18810-503: The hotspot's activity declined, the crust beneath the embayment region cooled, contracted and subsided to a depth of 2.6 km, and around 80 million years ago the Reelfoot Rift formed a trough that was flooded by the Gulf of Mexico . As sea levels dropped, the Mississippi and other rivers extended their courses into the embayment , which gradually became filled with sediment with the Mississippi River at its center. Through
18981-491: The ice sheet left behind a large amount of meltwater ( Lake Algonquin , Lake Chicago , Glacial Lake Iroquois , and Champlain Sea ) that filled up the basins that the glaciers had carved, thus creating the Great Lakes as they are today. Because of the uneven nature of glacier erosion , some higher hills became Great Lakes islands. The Niagara Escarpment follows the contour of the Great Lakes between New York and Wisconsin. Land below
19152-554: The key indicators even in the current era of sophisticated analyses and measuring instruments. According to the bi-national (U.S. and Canadian) resource book, The Great Lakes: An Environmental Atlas and Resource Book : "The largest Great Lakes fish harvests were recorded in 1889 and 1899 at some 67,000 tonnes (66,000 long tons; 74,000 short tons) [147 million pounds]." By 1801, the New York Legislature found it necessary to pass regulations curtailing obstructions to
19323-612: The lake and causing blooms," said Michael McKay, executive director of the Great Lakes Institute for Environmental Research (GLIER) at the University of Windsor . The largest Lake Erie bloom to date occurred in 2015, exceeding the severity index at 10.5 and in 2011 at a 10. In early August 2019, satellite images depicted a bloom stretching up to 1,300 square kilometres on Lake Erie, with the heaviest concentration near Toledo, Ohio . A large bloom does not necessarily mean
19494-650: The lake shore as far north as the Grand Traverse Bay . Near Collingwood, Ontario , commercial fruit orchards, including a few wineries, exist near the shoreline of southern Nottawasaga Bay . The eastern shore of Lake Michigan and the southern shore of Lake Erie have many successful wineries because of the lakes' moderating effects, as do the large commercial fruit and wine growing areas of the Niagara Peninsula located between Lake Erie and Lake Ontario. A similar phenomenon allows wineries to flourish in
19665-457: The lake. For example, 90% of the grain shipped from Chicago traveled by ships east over Lake Michigan during the antebellum years. The volume rarely fell below 50% after the Civil War even with the major expansion of railroad shipping . The first person to reach the deep bottom of Lake Michigan was J. Val Klump , a scientist at the University of Wisconsin–Milwaukee in 1985. Klump reached
19836-538: The lakes has been observed since records began in 1918. The water level of Lake Michigan–Huron had remained fairly constant over the 20th century. Recent lake levels include record low levels in 2013 in Lakes Superior, Erie, and Michigan-Huron, followed by record high levels in 2020 in the same lakes. The water level in Lake Ontario has remained relatively constant in the same time period, hovering around
20007-431: The lakes that are too large to pass the locks and enter the ocean. Despite their vast size, large sections of the Great Lakes freeze in winter, interrupting most shipping. Some icebreakers ply the lakes. Lake Michigan is connected by the Illinois Waterway to the Gulf of Mexico via the Illinois River and the Mississippi River. Commercial tug-and-barge traffic on these waterways is heavy. Pleasure boats can enter or exit
20178-537: The lakes' levels: diversion (the transfer of water to other watersheds) and consumption (substantially done today by the use of lake water to power and cool electric generation plants, resulting in evaporation). Outflows through the Chicago Sanitary and Ship Canal is more than balanced by artificial inflows via the Ogoki River and Long Lake/ Kenogami River diversions. Fluctuation of the water levels in
20349-408: The lakes. Only barges can access the Illinois Waterway system providing access to the Gulf of Mexico via the Mississippi River. Despite their vast size, large sections of the Great Lakes freeze over in winter, interrupting most shipping from January to March. Some icebreakers ply the lakes, keeping the shipping lanes open through other periods of ice on the lakes. The Great Lakes are connected by
20520-415: The lakes. The province of Ontario does not border Lake Michigan, and the state of Michigan does not border Lake Ontario. New York and Wisconsin's jurisdictions extend into two lakes, and each of the remaining states into one of the lakes. As the surfaces of Lakes Superior, Huron, Michigan, and Erie are all approximately the same elevation above sea level, while Lake Ontario is significantly lower, and because
20691-470: The largest lake entirely within one country by surface area ( Lake Baikal in Russia is larger by water volume) and the fifth-largest lake in the world. It is the larger half of Lake Michigan–Huron , which is the largest body of fresh water in the world by surface area. It is 307 miles (494 km) long by 118 miles (190 km) wide with a shoreline 1,640 miles (2,640 km) long. The lake's average depth
20862-402: The last two decades, this number was only 160 million short tons (145 million metric tons) per year. The reduction in sediment transported down the Mississippi River is the result of engineering modification of the Mississippi, Missouri, and Ohio rivers and their tributaries by dams, meander cutoffs , river-training structures, and bank revetments and soil erosion control programs in
21033-455: The late 1960s, successful stocking programs for Pacific salmon led to the development of Lake Michigan's charter fishing industry. Like all of the Great Lakes, Lake Michigan is today used as a major mode of transport for bulk goods. In 2002, 162 million net tons of dry bulk cargo were moved via the Lakes. This was, in order of volume: iron ore, grain and potash . The iron ore and much of
21204-468: The latter as the lower lakes and Lakes Michigan, Huron, and Superior as the upper lakes. This corresponds to thinking of lakes Erie and Ontario as "down south" and the others as "up north". Vessels sailing north on Lake Michigan are considered "upbound" even though they are sailing toward its effluent current. Lakes Huron and Michigan are sometimes considered a single lake, called Lake Michigan–Huron, because they are one hydrological body of water connected by
21375-494: The launch of the bi-national Great Lakes Fishery Commission . Several species of exotic water fleas have accidentally been introduced into the Great Lakes, such as the spiny waterflea, Bythotrephes longimanus , and the fishhook waterflea, Cercopagis pengoi , potentially having an effect on the zooplankton population. Several species of crayfish have also been introduced that may contend with native crayfish populations. More recently an electric fence has been set up across
21546-502: The lower 10 miles (16 km) of the Kaskaskia River, forming a new Mississippi channel and cutting off the town from the rest of the state. Later flooding destroyed most of the remaining town, including the original State House. Today, the remaining 2,300 acres (930 ha) island and community of 14 residents is known as an enclave of Illinois and is accessible only from the Missouri side. The New Madrid Seismic Zone , along
21717-443: The lower water levels in 2013 were a combination of the "lack of a large snowpack" in the winter of 2011/2012 coupled with very hot and dry conditions in the summer of 2012. Since then water levels rebounded, rising more than 6 feet (1.8 meters) to historical record high levels. Lake Michigan, like the other Great Lakes, supplies drinking water to millions of people in bordering areas. The Great Lakes are collectively administered by
21888-575: The mid-19th century. Several ferries currently operate on the Great Lakes to carry passengers to various islands, including Beaver Island and Bois Blanc Island (Michigan) . Currently, two car ferry services traverse Lake Michigan from around April to November: the SS Badger, a steamer from Ludington, Michigan, to Manitowoc, Wisconsin, and the Lake Express , a high speed catamaran from Milwaukee to Muskegon, Michigan. The Great Lakes Circle Tour ,
22059-476: The natural migrations of Atlantic salmon from Lake Erie into their spawning channels. In the early 19th century, the government of Upper Canada found it necessary to introduce similar legislation prohibiting the use of weirs and nets at the mouths of Lake Ontario's tributaries. Other protective legislation was passed, but enforcement remained difficult. On both sides of the Canada–United States border,
22230-449: The new river channel, contiguous with the adjacent state. Also, due to a meander in the river, a small part of western Kentucky is contiguous with Tennessee but isolated from the rest of its state. Many of the communities along the Mississippi River are listed below; most have either historic significance or cultural lore connecting them to the river. They are sequenced from the source of the river to its end. The road crossing highest on
22401-698: The northeast. The word michigan is believed to come from the Ojibwe ᒥᓯᑲᒥ ( michi-gami or mishigami ), meaning "great water". Some of the most well-studied early human inhabitants of the Lake Michigan region were the Hopewell Native Americans . Their culture declined after 800 AD, when, for the following few hundred years, the region was the home of peoples known as the Late Woodland Native Americans . In
22572-415: The order amphipoda ), two types of copepods , and the deepwater sculpin (a spiny, large-headed fish). The Great Lakes are an important source of fishing . Early European settlers were astounded by both the variety and quantity of fish; there were 150 different species in the Great Lakes. Throughout history, fish populations were the early indicator of the condition of the Lakes and have remained one of
22743-516: The outflows of Michigan-Huron and Erie are not regulated at all. Ontario is the most tightly regulated, with its outflow controlled by the Moses-Saunders Power Dam , which explains its consistent historical levels. The Great Lakes contain 21% of the world's surface fresh water: 5,472 cubic miles (22,810 km ), or 6.0×10 U.S. gallons, that is 6 quadrillion U.S. gallons, (2.3×10 liters). The lakes contain about 84% of
22914-549: The past 5,000 years, caused the coastline of south Louisiana to advance toward the Gulf from 15 to 50 miles (24 to 80 km). The currently active delta lobe is called the Birdfoot Delta, after its shape, or the Balize Delta , after La Balize, Louisiana , the first French settlement at the mouth of the Mississippi. The current form of the Mississippi River basin was largely shaped by the Laurentide Ice Sheet of
23085-549: The plume did not mix with the surrounding sea water immediately. Instead, it stayed intact as it flowed through the Gulf of Mexico, into the Straits of Florida , and entered the Gulf Stream . The Mississippi River water rounded the tip of Florida and traveled up the southeast coast to the latitude of Georgia before finally mixing in so thoroughly with the ocean that it could no longer be detected by MODIS. Over geologic time,
23256-516: The proliferation of dams and impoundments have multiplied, necessitating more regulatory efforts. Concerns by the mid-19th century included obstructions in the rivers which prevented salmon and lake sturgeon from reaching their spawning grounds. The Wisconsin Fisheries Commission noted a reduction of roughly 25% in general fish harvests by 1875. The states have removed dams from rivers where necessary. Overfishing has been cited as
23427-612: The river's silt deposits, the Mississippi embayment is one of the most fertile regions of the United States; steamboats were widely used in the 19th and early 20th centuries to ship agricultural and industrial goods. During the American Civil War , the Mississippi's capture by Union forces marked a turning point towards victory , due to the river's strategic importance to the Confederate war effort. Because of
23598-479: The river, although the Mississippi defines part of the boundary of each of these states. In all of these cases, the middle of the riverbed at the time the borders were established was used as the line to define the borders between adjacent states. In various areas, the river has since shifted, but the state borders have not changed, still following the former bed of the Mississippi River as of their establishment, leaving several small isolated areas of one state across
23769-552: The river. Due to its size and importance, it has been nicknamed The Mighty Mississippi River or simply The Mighty Mississippi . The Mississippi River can be divided into three sections: the Upper Mississippi , the river from its headwaters to the confluence with the Missouri River; the Middle Mississippi, which is downriver from the Missouri to the Ohio River; and the Lower Mississippi , which flows from
23940-428: The routine discharge of untreated sewage during the 1970s and 1980s. The International Joint Commission in 2009 summarized the change: "Since the early 1970s, the level of treatment to reduce pollution from waste water discharges to the Great Lakes has improved considerably. This is a result of significant expenditures to date on both infrastructure and technology, and robust regulatory systems that have proven to be, on
24111-436: The shoreline of all the lakes would cover a distance roughly equivalent to travelling half-way around the world at the equator. A notable modern phenomenon is the formation of ice volcanoes over the lakes during wintertime. Storm-generated waves carve the lakes' ice sheet and create conical mounds through the eruption of water and slush. The process is only well-documented in the Great Lakes, and has been credited with sparing
24282-524: The shoreline, the dunes rise several hundred feet above the lake surface. Large dune formations can be seen in many state parks, national forests and national parks along the Indiana and Michigan shoreline. Some of the most expansive and unique dune formations can be found at Indiana Dunes National Park , Saugatuck Dunes State Park , Warren Dunes State Park , Hoffmaster State Park , Silver Lake State Park , Ludington State Park , and Sleeping Bear Dunes National Lakeshore . Small dune formations can be found on
24453-400: The site of the head of navigation of the river. The Upper Mississippi has a number of natural and artificial lakes, with its widest point being Lake Winnibigoshish , near Grand Rapids, Minnesota , over 11 miles (18 km) across. Lake Onalaska , created by Lock and Dam No. 7 , near La Crosse, Wisconsin , is more than 4 miles (6.4 km) wide. Lake Pepin , a natural lake formed behind
24624-602: The southern shorelines from worse rocky erosion. It has been estimated that the foundational geology that created the conditions shaping the present day upper Great Lakes was laid from 1.1 to 1.2 billion years ago, when two previously fused tectonic plates split apart and created the Midcontinent Rift , which crossed the Great Lakes Tectonic Zone . A valley was formed providing a basin that eventually became modern day Lake Superior. When
24795-532: The state line still follows the old channel. The town of Kaskaskia, Illinois once stood on a peninsula at the confluence of the Mississippi and Kaskaskia (Okaw) Rivers . Founded as a French colonial community, it later became the capital of the Illinois Territory and was the first state capital of Illinois until 1819. Beginning in 1844, successive flooding caused the Mississippi River to slowly encroach east. A major flood in 1881 caused it to overtake
24966-411: The states and the two provinces, and the enactment of a United States federal law. Environmental problems can still plague the lake. Steel mills and refineries operate near the Indiana shoreline. The Chicago Tribune reported that BP is a major polluter, dumping thousands of pounds of raw sludge into the lake every day from its Whiting, Indiana , oil refinery. In March 2014 BP's Whiting refinery
25137-620: The stone and coal are used in the steel industry. There is also some shipping of liquid and containerized cargo, but most container vessels cannot pass the locks on the Saint Lawrence Seaway because the ships are too wide. The total amount of shipping on the lakes has been on a downward trend for several years. The Port of Chicago , operated by the Illinois International Port District , has grain (14 million bushels) and bulk liquid (800,000 barrels) storage facilities along Lake Calumet . The central element of
25308-412: The substantial growth of cities and the larger ships and barges that replaced steamboats, the first decades of the 20th century saw the construction of massive engineering works such as levees , locks and dams , often built in combination. A major focus of this work has been to prevent the lower Mississippi from shifting into the channel of the Atchafalaya River and bypassing New Orleans . Since
25479-414: The surface freshwater of North America; if the water were evenly distributed over the entire continent's land area, it would reach a depth of 5 feet (1.5 meters). This is enough water to cover the 48 contiguous U.S. states to a uniform depth of 9.5 feet (2.9 m). Although the lakes contain a large percentage of the world's fresh water, the Great Lakes supply only a small portion of U.S. drinking water on
25650-525: The total photosynthesis. By taking CO 2 out of the water to photosynthesize, diatoms help to stabilize the pH of the water, as CO 2 would react with water to produce carbonic acid . Mississippi River The Mississippi River is the primary river of the largest drainage basin in the United States . From its traditional source of Lake Itasca in northern Minnesota , it flows generally south for 2,340 miles (3,766 km) to
25821-562: The treatment plant, are temporarily overwhelmed by heavy rainstorms. Local sewage treatment authorities then must release untreated effluent, a mix of rainwater and sewage, into local water bodies. While enormous public investments such as the Deep Tunnel projects in Chicago and Milwaukee have greatly reduced the frequency and volume of these events, they have not been eliminated. The number of such overflow events in Ontario, for example,
25992-532: The tributary rivers into the Great Lakes also dislocated sediments. In 1884, the New York Fish Commission determined that the dumping of sawmill waste (chips and sawdust) had impacted fish populations. The first U.S. Clean Water Act , passed by a Congressional override after being vetoed by U.S. President Richard Nixon in 1972, was a key piece of legislation, along with the bi-national Great Lakes Water Quality Agreement signed by Canada and
26163-502: The two cities. The Lake Express , established in 2004, carries passengers and vehicles across the lake between Milwaukee, Wisconsin, and Muskegon, Michigan. Tourism and recreation are major industries on all of the Great Lakes. A few small cruise ships operate on Lake Michigan, including a couple of sailing ships. Many other water sports are practiced on the lakes, such as yachting, sea kayaking, diving, kitesurfing and lake surfing. Great Lakes passenger steamers have been operating since
26334-573: The upper and lower river, the Mississippi is further controlled by thousands of wing dikes that moderate the river's flow in order to maintain an open navigation channel and prevent the river from eroding its banks. The head of navigation on the Mississippi is the St. Anthony Falls Lock. Before the Coon Rapids Dam in Coon Rapids, Minnesota , was built in 1913, steamboats could occasionally go upstream as far as Saint Cloud, Minnesota , depending on river conditions. The uppermost lock and dam on
26505-495: The vitality of native fish populations. Fisheries in inland waters of the United States are small compared to marine fisheries. The largest fisheries are the landings from the Great Lakes, worth about $ 14 million in 2001. Michigan's commercial fishery today consists mainly of 150 tribe-licensed commercial fishing operations through the Chippewa-Ottawa Resource Authority and tribes belonging to
26676-416: The warmer and shallower portions of the system such as Lake Erie, Saginaw Bay , Green Bay , and the southernmost portion of Lake Michigan. By the mid-1980s, most jurisdictions bordering the Great Lakes had controlled phosphate detergents . Blue-green algae, or cyanobacteria blooms, have been problematic on Lake Erie since 2011. "Not enough is being done to stop fertilizer and phosphorus from getting into
26847-416: The water is usually clear and cool, between 55 and 80 °F (13 and 27 °C), even in the late summer months. However, because prevailing westerly winds tend to move the surface water toward the east, there is a flow of warmer water to the Michigan shore in the summer. The sand dunes located on the east shore of Lake Michigan are the largest freshwater dune system in the world. In multiple locations along
27018-607: The west and north of Lake Michigan. The Straits of Mackinac were an important Native American travel corridor and fur-trade route. Located on the southern side of the straits sits the town of Mackinaw City, Michigan , the site of Fort Michilimackinac (a reconstructed French fort founded in 1715); on the northern side is St. Ignace, Michigan , site of a French Catholic mission to the Indians (founded in 1671). In 1673, Jacques Marquette , Louis Jolliet , and their crew of five Métis voyageurs followed Lake Michigan to Green Bay and up
27189-430: The west pick up the air and moisture from the lake surface, which is slightly warmer in relation to the cold surface winds above. As the slightly warmer, moist air passes over the colder land surface, the moisture often produces concentrated, heavy snowfall that sets up in bands or "streamers". This is similar to the effect of warmer air dropping snow as it passes over mountain ranges. During freezing weather with high winds,
27360-427: The west, and warm, wet tropical systems from the south and the Gulf of Mexico. The lakes have a moderating effect on the climate; they can also increase precipitation totals and produce lake effect snowfall . The Great Lakes can have an effect on regional weather called lake-effect snow , which is sometimes very localized. Even late in winter, the lakes often have no icepack in the middle. The prevailing winds from
27531-666: The western shore of Lake Michigan at Illinois Beach State Park , and moderate-sized dune formations can be found in Kohler-Andrae State Park and Point Beach State Forest in Wisconsin. A large dune formation can be found in Whitefish Dunes State Park in Wisconsin in the Door Peninsula . Lake Michigan beaches in Northern Michigan are the only place in the world, aside from a few inland lakes in that region, where Petoskey stones ,
27702-480: The whole, quite effective." The commission reported that all urban sewage treatment systems on the U.S. side of the lakes had implemented secondary treatment, as had all on the Canadian side except for five small systems. Though contrary to federal laws in both countries, those treatment system upgrades have not yet eliminated combined sewer overflow events. This describes when older sewerage systems, which combine storm water with sewage into single sewers heading to
27873-625: The wildlife population. This program was so successful that the introduced population of trout and salmon exploded, resulting in the creation of a large sport fishery for these introduced species. Lake Michigan is now stocked annually with steelhead, brown trout, and coho and chinook salmon, which have also begun natural reproduction in some Lake Michigan tributaries. However, several introduced invasive species, such as lampreys, round goby , zebra mussels and quagga mussels , continue to cause major changes in water clarity and fertility, resulting in knock-on changes to Lake Michigan's ecosystem, threatening
28044-479: The world by volume. On average, the Mississippi has 8% the flow of the Amazon River , which moves nearly 7 million cubic feet per second (200,000 m /s) during wet seasons. Before 1900, the Mississippi River transported an estimated 440 million short tons (400 million metric tons) of sediment per year from the interior of the United States to coastal Louisiana and the Gulf of Mexico. During
28215-472: The world's surface fresh water by volume. The total surface is 94,250 square miles (244,106 km ), and the total volume (measured at the low water datum) is 5,439 cubic miles (22,671 km ), slightly less than the volume of Lake Baikal (5,666 cu mi or 23,615 km , 22–23% of the world's surface fresh water). Because of their sea-like characteristics, such as rolling waves, sustained winds, strong currents, great depths, and distant horizons,
28386-567: The world. The second-largest island is Isle Royale in Lake Superior. Both of these islands are large enough to contain multiple lakes themselves—for instance, Manitoulin Island's Lake Manitou is the world's largest lake on a freshwater island. Some of these lakes even have their own islands, like Treasure Island in Lake Mindemoya in Manitoulin Island. The Great Lakes also have several peninsulas between them, including
28557-523: The zooplankton community of the lake. Scientists understand that the micro-aquatic life of the lakes is abundant but know very little about some of the most plentiful microbes and their environmental effects in the Great Lakes. Although a drop of lake water may contain 1 million bacteria cells and 10 million viruses , only since 2012 has there been a long-term study of the lakes' micro-organisms. Between 2012 and 2019 more than 160 new species have been discovered. Native habitats and ecoregions in
28728-558: Was Ontario's Collingwood Harbour in 1994; Ontario's Severn Sound followed in 2003. Presque Isle Bay in Pennsylvania is formally listed as in recovery, as is Ontario's Spanish Harbour. Dozens of other Areas of Concern have received partial cleanups such as the Rouge River (Michigan) and Waukegan Harbor (Illinois). Phosphate detergents were historically a major source of nutrient to the Great Lakes algae blooms in particular in
28899-602: Was eclipsed in January 2013. In January 2013, Lake Michigan's monthly mean water levels dipped to an all-time low of 576.2 ft (175.6 m), reaching their lowest ebb since record keeping began in 1918. The lakes were 29 in (0.74 m) below their long-term average and had declined 17 inches since January 2012. Keith Kompoltowicz, chief of watershed hydrology for the U.S. Army Corps of Engineers ' district office in Detroit , explained that biggest factors leading to
29070-517: Was eliminated as the mussels were harvested for use as buttons by early Great Lakes entrepreneurs. The Great Lakes: An Environmental Atlas and Resource Book (1972) notes: "Only pockets remain of the once large commercial fishery." Water quality improvements realized during the 1970s and 1980s, combined with successful salmonid stocking programs, have enabled the growth of a large recreational fishery. The last commercial fisherman left Milwaukee in 2011 because of overfishing and anthropogenic changes to
29241-568: Was responsible for spilling more than 1,600 US gallons (6,100 L) of oil into the lake. Lake Michigan has many beaches. The region is often referred to as the " Third Coast " of the United States, after those of the Atlantic Ocean and the Pacific Ocean . The sand is often soft and off-white, known as " singing sands " because of the squeaking noise (caused by high quartz content) it emits when walked upon. Some beaches have sand dunes covered in green beach grass and sand cherries , and
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