Mississippi River Basin
   HOME

TheInfoList



OR:

The Mississippi River is the second-longest river and chief
river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
of the second-largest drainage system in
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, second only to the
Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
drainage system. From its traditional source of
Lake Itasca Lake Itasca is a small glacial lake, approximately in area. Located in southeastern Clearwater County, in the Headwaters area of north central Minnesota, it is notable for being the headwater of the Mississippi River. The lake is in Itasca Sta ...
in northern
Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
, it flows generally south for to the
Mississippi River Delta The Mississippi River Delta is the confluence of the Mississippi River with the Gulf of Mexico in Louisiana, southeastern United States. The river delta is a area of land that stretches from Vermilion Bay on the west, to the Chandeleur Isla ...
in the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...
. With its many
tributaries A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage b ...
, the Mississippi's
watershed Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, called a "watershe ...
drains all or parts of 32
U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...
s and two
Canadian provinces Within the geographical areas of Canada, the ten provinces and three territories are sub-national administrative divisions under the jurisdiction of the Canadian Constitution. In the 1867 Canadian Confederation, three provinces of British North ...
between the
Rocky ''Rocky'' is a 1976 American sports drama film directed by John G. Avildsen and written by and starring Sylvester Stallone. It is the first installment in the ''Rocky'' franchise and stars Talia Shire, Burt Young, Carl Weathers, and Burgess M ...
and Appalachian mountains. The
main stem In hydrology, a mainstem (or trunk) is "the primary downstream segment of a river, as contrasted to its tributaries". Water enters the mainstem from the river's drainage basin, the land area through which the mainstem and its tributaries flow.. A ...
is entirely within the United States; the total
drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...
is , of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of
Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
,
Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
,
Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...
,
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
,
Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
,
Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to ...
,
Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
,
Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
,
Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
, and
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Most were
hunter-gatherer A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...
s, but some, such as the
Mound Builders A number of pre-Columbian cultures are collectively termed "Mound Builders". The term does not refer to a specific people or archaeological culture, but refers to the characteristic mound earthworks erected for an extended period of more than 5 ...
, formed prolific agricultural and urban civilizations. 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 first as a barrier, forming borders for
New Spain New Spain, officially the Viceroyalty of New Spain ( es, Virreinato de Nueva España, ), or Kingdom of New Spain, was an integral territorial entity of the Spanish Empire, established by Habsburg Spain during the Spanish colonization of the Am ...
,
New France New France (french: Nouvelle-France) was the area colonized by France in North America, beginning with the exploration of the Gulf of Saint Lawrence by Jacques Cartier in 1534 and ending with the cession of New France to Great Britain and Spai ...
, and the early United States, and then as a vital transportation artery and communications link. In the 19th century, during the height of the ideology of
manifest destiny Manifest destiny was a cultural belief in the 19th century in the United States, 19th-century United States that American settlers were destined to expand across North America. There were three basic tenets to the concept: * The special vir ...
, the Mississippi and several western tributaries, most notably the
Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
, formed pathways for the western expansion of the United States. Formed from thick layers of the river's
silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...
deposits, the
Mississippi embayment The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its conflu ...
is one of the most fertile regions of the United States;
steamboats A steamboat is a boat that is marine propulsion, propelled primarily by marine steam engine, steam power, typically driving propellers or Paddle steamer, paddlewheels. Steamboats sometimes use the ship prefix, prefix designation SS, S.S. or S/S ...
were widely used in the 19th and early 20th centuries to ship agricultural and industrial goods. During the
American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...
, the Mississippi's capture by
Union Union commonly refers to: * Trade union, an organization of workers * Union (set theory), in mathematics, a fundamental operation on sets Union may also refer to: Arts and entertainment Music * Union (band), an American rock group ** ''Un ...
forces marked a turning point towards victory, due to the river's strategic importance to the
Confederate Confederacy or confederate may refer to: States or communities * Confederate state or confederation, a union of sovereign groups or communities * Confederate States of America, a confederation of secessionist American states that existed between 1 ...
war effort. Because of the substantial growth of cities and the larger ships and
barge Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels ...
s that replaced steamboats, the first decades of the 20th century saw the construction of massive engineering works such as
levee A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...
s,
locks Lock(s) may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance *Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainment * ''Lock ...
and
dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...
s, 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 The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
and bypassing
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
. Since 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 Dead zones are hypoxic (low-oxygen) areas in the world's oceans and large lakes. Hypoxia occurs when dissolved oxygen (DO) concentration falls to or below 2 mg of O2/liter. When a body of water experiences hypoxic conditions, aquatic flora and ...
.


Name and significance

The word Mississippi itself comes from , the French rendering of the
Anishinaabe The Anishinaabeg (adjectival: Anishinaabe) are a group of culturally related Indigenous peoples present in the Great Lakes region of Canada and the United States. They include the Ojibwe (including Saulteaux and Oji-Cree), Odawa, Potawatomi, ...
(
Ojibwe The Ojibwe, Ojibwa, Chippewa, or Saulteaux are an Anishinaabe people in what is currently southern Canada, the northern Midwestern United States, and Northern Plains. According to the U.S. census, in the United States Ojibwe people are one of ...
or
Algonquin Algonquin or Algonquian—and the variation Algonki(a)n—may refer to: Languages and peoples *Algonquian languages, a large subfamily of Native American languages in a wide swath of eastern North America from Canada to Virginia **Algonquin la ...
) name for the river, (Great River). In the 18th century, the river was the primary western boundary of the young United States, and since the country's expansion westward, the Mississippi River has been a convenient line dividing the Western United States from the Eastern, Southern, and Midwestern regions. This is symbolized by the
Gateway Arch The Gateway Arch is a monument in St. Louis, Missouri, United States. Clad in stainless steel and built in the form of a weighted catenary arch, it is the world's tallest arch and Missouri's tallest accessible building. Some sources conside ...
in St. Louis and the phrase "
Trans-Mississippi Trans-Mississippi was a common name of the geographic area west of the Mississippi River during the 19th century. The area included Arkansas, Louisiana, Missouri, Texas, Indian Territory (now Oklahoma), and many other territories. The term "Tr ...
" as used in the name of the
Trans-Mississippi Exposition The Trans-Mississippi and International Exposition was a world's fair held in Omaha, Nebraska from June 1 to November 1 of 1898. Its goal was to showcase the development of the entire West, stretching from the Mississippi River to the Pacific Coa ...
. 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 The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdiction ...
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 market A media market, broadcast market, media region, designated market area (DMA), television market area, or simply market is a region where the population can receive the same (or similar) television and radio station offerings, and may also incl ...
s along the river.


Divisions

The Mississippi River can be divided into three sections: the
Upper Mississippi The Upper Mississippi River is the portion of the Mississippi River upstream of St. Louis, Missouri, United States, at the confluence of its main tributary, the Missouri River. History In terms of geologic and hydrographic history, the Upper ...
, 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 The Lower Mississippi River is the portion of the Mississippi River downstream of Cairo, Illinois. From the confluence of the Ohio River and Upper Mississippi River at Cairo, the Lower flows just under 1000 miles (1600 km) to the Gulf o ...
, which flows from the Ohio to the Gulf of Mexico.


Upper Mississippi

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 headwaters, from the source to
Saint Anthony Falls Saint Anthony Falls, or the Falls of Saint Anthony ( dak, italics=no, Owámniyomni, ) located at the northeastern edge of downtown Minneapolis, Minnesota, is the only natural major waterfall on the Mississippi River. Throughout the mid-to-late 1 ...
in
Minneapolis, Minnesota Minneapolis () is the largest city in Minnesota, United States, and the county seat of Hennepin County. The city is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks and waterfalls. Minneapolis has its origins ...
; and # A navigable channel, formed by a series of man-made lakes between Minneapolis and St. Louis, Missouri, some . The source of the Upper Mississippi branch is traditionally accepted as
Lake Itasca Lake Itasca is a small glacial lake, approximately in area. Located in southeastern Clearwater County, in the Headwaters area of north central Minnesota, it is notable for being the headwater of the Mississippi River. The lake is in Itasca Sta ...
, above sea level in
Itasca State Park Itasca State Park (pronounced eye-ta-ska) is a state park of Minnesota, United States, and contains the headwaters of the Mississippi River. The park spans of northern Minnesota, and is located about north of Park Rapids, Minnesota and from Ba ...
in
Clearwater County, Minnesota Clearwater County is a county in the northwestern part of the U.S. state of Minnesota. As of the 2020 census, the population was 8,524. Its county seat is Bagley. Clearwater County is home to Lake Itasca, the source of the Mississippi River. ...
. The name ''Itasca'' was chosen to designate the "true head" of the Mississippi River as a combination of the last four letters of the Latin word for truth () and the first two letters of the Latin word for head (). However, the lake is in turn fed by a number of smaller streams. From its origin at Lake Itasca to
St. Louis, Missouri St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi River, Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the Greater St. Louis, ...
, the waterway's flow is moderated by 43 dams. Fourteen of these dams are located above Minneapolis in the
headwater The headwaters of a river or stream is the farthest place in that river or stream from its estuary or downstream confluence with another river, as measured along the course of the river. It is also known as a river's source. Definition The ...
s 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 Saint Paul (abbreviated St. Paul) is the List of capitals in the United States, capital of the U.S. state of Minnesota and the county seat of Ramsey County, Minnesota, Ramsey County. Situated on high bluffs overlooking a bend in the Mississip ...
, and continuing throughout the upper and lower river, the Mississippi is further controlled by thousands of
wing dike A wing dam or wing dike is a man made barrier that, unlike a conventional dam, only extends partway into a river. These structures force water into a fast-moving center channel which reduces the rate of sediment accumulation, while slowing water f ...
s 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 The head of navigation is the farthest point above the mouth of a river that can be navigated by ships. Determining the head of navigation can be subjective on many streams, as the point may vary greatly with the size or the draft of the ship be ...
on the Mississippi is the St. Anthony Falls Lock. Before the Coon Rapids Dam in
Coon Rapids, Minnesota Coon Rapids is a northern suburb of Minneapolis, and is the largest city in Anoka County, Minnesota, United States. The population was 63,599 at the 2020 census, making it the fifteenth largest city in Minnesota and the seventh largest Twin Ci ...
, was built in 1913, steamboats could occasionally go upstream as far as
Saint Cloud, Minnesota St. Cloud is a city in the U.S. state of Minnesota and the largest population center in the state's central region. The population was 68,881 at the 2020 census, making it Minnesota's 12th-largest city. St. Cloud is the county seat of Stearn ...
, depending on river conditions. The uppermost lock and dam on the Upper Mississippi River is the Upper St. Anthony Falls Lock and Dam in Minneapolis. Above the dam, the river's elevation is . Below the dam, the river's elevation is . This 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 Saint Anthony Falls, or the Falls of Saint Anthony ( dak, italics=no, Owámniyomni, ) located at the northeastern edge of downtown Minneapolis, Minnesota, is the only natural major waterfall on the Mississippi River. Throughout the mid-to-late 1 ...
is the only true waterfall on the entire Mississippi River. The water elevation continues to drop steeply as it passes through the
gorge A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...
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 Coon Rapids is a northern suburb of Minneapolis, and is the largest city in Anoka County, Minnesota, United States. The population was 63,599 at the 2020 census, making it the fifteenth largest city in Minnesota and the seventh largest Twin C ...
. However, the Locks were closed in 2015 to control the spread of invasive Asian carp, making Minneapolis once again 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 Lake Winnibigoshish is a body of water in north central Minnesota in the Chippewa National Forest. Its name comes from the Ojibwe language ''Wiinibiigoonzhish'', a diminutive and pejorative form of ''Wiinibiig'', meaning "filthy water" (i.e., "br ...
, near
Grand Rapids, Minnesota Grand Rapids is a city in Itasca County, Minnesota, United States, and it is the county seat. The population is 11,126 according to the 2020 census. The city is named for the long rapids in the Mississippi River which was the uppermost limit ...
, over across. Lake Onalaska, created by Lock and Dam No. 7, near
La Crosse, Wisconsin La Crosse is a city in the U.S. state of Wisconsin and the county seat of La Crosse County. Positioned alongside the Mississippi River, La Crosse is the largest city on Wisconsin's western border. La Crosse's population as of the 2020 census w ...
, is more than wide.
Lake Pepin Lake Pepin is a naturally occurring lake on the Mississippi River on the border between the U.S. states of Minnesota and Wisconsin. It is located in a valley carved by the outflow of an enormous glacial lake at the end of the last Ice Age. The ...
, a natural lake formed behind the delta of the Chippewa River of Wisconsin as it enters the Upper Mississippi, is more than wide. By the time the Upper Mississippi reaches
Saint Paul Paul; grc, Παῦλος, translit=Paulos; cop, ⲡⲁⲩⲗⲟⲥ; hbo, פאולוס השליח (previously called Saul of Tarsus;; ar, بولس الطرسوسي; grc, Σαῦλος Ταρσεύς, Saũlos Tarseús; tr, Tarsuslu Pavlus; ...
, Minnesota, below Lock and Dam No. 1, it has dropped more than half its original elevation and is above sea level. From St. Paul to St. Louis, Missouri, the river elevation falls much more slowly and 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 The Minnesota River ( dak, Mnísota Wakpá) is a tributary of the Mississippi River, approximately 332 miles (534 km) long, in the U.S. state of Minnesota. It drains a watershed of in Minnesota and about in South Dakota and Iowa. It ris ...
at
Fort Snelling Fort Snelling is a former military fortification and National Historic Landmark in the U.S. state of Minnesota on the bluffs overlooking the confluence of the Minnesota and Mississippi Rivers. The military site was initially named Fort Saint Anth ...
in the
Twin Cities Twin cities are a special case of two neighboring cities or urban centres that grow into a single conurbation – or narrowly separated urban areas – over time. There are no formal criteria, but twin cities are generally comparable in statu ...
; the St. Croix River near
Prescott, Wisconsin Prescott is a city in Pierce County, Wisconsin, Pierce County, Wisconsin at the confluence of the St. Croix River (Wisconsin-Minnesota), St. Croix River and Mississippi River. The population was 4,258 at the 2010 census, making it the second-large ...
; the Cannon River near
Red Wing, Minnesota Red Wing is a city in Goodhue County, Minnesota, Goodhue County, Minnesota, United States, along the upper Mississippi River. The population was 16,547 at the 2020 United States Census, 2020 census. It is the county seat of Goodhue County. This ...
; the
Zumbro River The Zumbro River is a tributary of the Mississippi River in the Driftless Area of southeastern Minnesota in the United States. It is longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, access ...
at
Wabasha, Minnesota Wabasha is a city and the county seat of Wabasha County, Minnesota, Wabasha County, Minnesota. The population was 2,559 at the time of the 2020 United States Census, 2020 census. It is on the Mississippi River, near its confluence with the Zumbro ...
; the
Black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have o ...
,
La Crosse La Crosse is a city in the U.S. state of Wisconsin and the county seat of La Crosse County, Wisconsin, La Crosse County. Positioned alongside the Mississippi River, La Crosse is the largest city on Wisconsin's western border. La Crosse's populat ...
, and
Root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...
rivers in
La Crosse, Wisconsin La Crosse is a city in the U.S. state of Wisconsin and the county seat of La Crosse County. Positioned alongside the Mississippi River, La Crosse is the largest city on Wisconsin's western border. La Crosse's population as of the 2020 census w ...
; the
Wisconsin River The Wisconsin River is a tributary of the Mississippi River in the U.S. state of Wisconsin. At approximately 430 miles (692 km) long, it is the state's longest river. The river's name, first recorded in 1673 by Jacques Marquette as "Meskousi ...
at
Prairie du Chien, Wisconsin Prairie du Chien () is a city in and the county seat of Crawford County, Wisconsin, United States. The population was 5,506 at the 2020 census. Its ZIP Code is 53821. Often referred to as Wisconsin's second oldest city, Prairie du Chien was esta ...
; the Rock River at the
Quad Cities The Quad Cities is a region of cities (originally four, see History) in the U.S. states of Iowa and Illinois: Davenport and Bettendorf in southeastern Iowa, and Rock Island, Moline and East Moline in northwestern Illinois. These cities are t ...
; the
Iowa River The Iowa River is a tributary of the Mississippi River in the state of Iowa in the United States. It is about longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed May 13, 2011 and is ...
near
Wapello, Iowa Wapello is a city in and the county seat of Louisa County, Iowa, United States. The population was 2,084 at the time of the 2020 census. Wapello is part of the Muscatine Micropolitan Statistical Area. History Wapello was platted in the late ...
; the
Skunk River The Skunk River is a tributary of the Mississippi River in the state of Iowa in the United States. Geography The Skunk River rises in two branches, the South Skunk ( long) and the North Skunk ( long).U.S. Geological Survey. National Hydrography ...
south of
Burlington, Iowa Burlington is a city in, and the county seat of, Des Moines County, Iowa, United States. The population was 23,982 in the 2020 census, a decline from the 26,839 population in 2000. Burlington is the center of a micropolitan area, which includes ...
; and the
Des Moines River The Des Moines River () is a tributary of the Mississippi River in the upper Midwestern United States that is approximately long from its farther headwaters.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe Na ...
at
Keokuk, Iowa Keokuk is a city in and a county seat of Lee County, Iowa, United States, along with Fort Madison. It is Iowa's southernmost city. The population was 9,900 at the time of the 2020 census. The city is named after the Sauk chief Keokuk, who is ...
. Other major tributaries of the Upper Mississippi include the Crow River in Minnesota, the Chippewa River in Wisconsin, the
Maquoketa River The Maquoketa River is a tributary of the Mississippi River, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed May 13, 2011 in northeastern Iowa in the United States. I ...
and the
Wapsipinicon River The Wapsipinicon River (, locally known as the Wapsi) is a tributary of the Mississippi River, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 13, 2011 starting n ...
in Iowa, and the
Illinois River The Illinois River ( mia, Inoka Siipiiwi) is a principal tributary of the Mississippi River and is approximately long. Located in the U.S. state of Illinois, it has a drainage basin of . The Illinois River begins at the confluence of the D ...
in Illinois. The Upper Mississippi is largely a multi-thread stream with many bars and islands. From its confluence with the St. Croix River downstream to
Dubuque, Iowa Dubuque (, ) is the county seat of Dubuque County, Iowa, United States, located along the Mississippi River. At the time of the 2020 United States Census, 2020 census, the population of Dubuque was 59,667. The city lies at the junction of Iowa, Il ...
, 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 Savanna is a city in Carroll County, Illinois, United States. The population was 2,783 at the 2020 census, down from 2,945 at the 2010 census. Savanna is located along the Mississippi River at the mouth of the Plum River. Going from north to so ...
. This topography contrasts strongly with the Lower Mississippi, which is a meandering river in a broad, flat area, only rarely flowing alongside a bluff (as at
Vicksburg, Mississippi Vicksburg is a historic city in Warren County, Mississippi, United States. It is the county seat, and the population at the 2010 census was 23,856. Located on a high bluff on the east bank of the Mississippi River across from Louisiana, Vic ...
).


Middle 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 St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi River, Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the Greater St. Louis, ...
, for to its confluence with the
Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...
at
Cairo, Illinois Cairo ( ) is the southernmost city in Illinois and the county seat of Alexander County. The city is located at the confluence of the Ohio and Mississippi rivers. Fort Defiance, a Civil War camp, was built here in 1862 by Union General Ulysses ...
. The Middle Mississippi is relatively free-flowing. From St. Louis to the Ohio River confluence, the Middle Mississippi falls over for an average rate of . At its confluence with the Ohio River, the Middle Mississippi is above sea level. Apart from the Missouri and Meramec rivers of Missouri and the
Kaskaskia River The Kaskaskia River is a tributary of the Mississippi River, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed May 13, 2011 in central and southern Illinois in the Un ...
of Illinois, no major tributaries enter the Middle Mississippi River.


Lower Mississippi

The Mississippi River 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 . At the confluence of the Ohio and the Middle Mississippi, the long-term mean discharge of the Ohio at Cairo, Illinois is , while the long-term mean discharge of the Mississippi at Thebes, Illinois (just upriver from Cairo) is . Thus, by volume, the main branch of the
Mississippi River system The Mississippi River System, also referred to as the Western Rivers, is a mostly riverine network of the United States which includes the Mississippi River and connecting waterways. The Mississippi River is the largest drainage basin in the Unit ...
at Cairo can be considered to be the Ohio River (and the
Allegheny River The Allegheny River ( ) is a long headwater stream of the Ohio River in western Pennsylvania and New York (state), New York. The Allegheny River runs from its headwaters just below the middle of Pennsylvania's northern border northwesterly into ...
further upstream), rather than the Middle Mississippi. In addition to the
Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...
, the major tributaries of the Lower Mississippi River are the White River, flowing in at the
White River National Wildlife Refuge The White River National Wildlife Refuge (officially Dale Bumpers White River National Wildlife Refuge) is a wildlife refuge located in Desha, Monroe, Phillips, and Arkansas counties in the U.S. state of Arkansas. The refuge is managed by the ...
in east-central Arkansas; the
Arkansas River The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United Stat ...
, joining the Mississippi at
Arkansas Post The Arkansas Post (french: Poste de Arkansea) (Spanish: ''Puesto de Arkansas''), formally the Arkansas Post National Memorial, was the first European settlement in the Mississippi Alluvial Plain and present-day U.S. state of Arkansas. In 168 ...
; the Big Black River in Mississippi; and the
Yazoo River The Yazoo River is a river in the U.S. states of Louisiana and Mississippi. It is considered by some to mark the southern boundary of what is called the Mississippi Delta, a broad floodplain that was cultivated for cotton plantations before the ...
, meeting the Mississippi at
Vicksburg, Mississippi Vicksburg is a historic city in Warren County, Mississippi, United States. It is the county seat, and the population at the 2010 census was 23,856. Located on a high bluff on the east bank of the Mississippi River across from Louisiana, Vic ...
. Deliberate water diversion at the
Old River Control Structure The Old River Control Structure is a floodgate system in a branch of the Mississippi River in central Louisiana. It regulates the flow of water from the Mississippi into the Atchafalaya River, thereby preventing the Mississippi River from chang ...
in
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
allows the
Atchafalaya River The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
in Louisiana to be a major
distributary A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel. Distributaries are a common feature of river deltas. The phenomenon is known as river bifurcation. The opposite of a distributar ...
of the Mississippi River, with 30% of the combined flow of the Mississippi and Red Rivers flowing to the Gulf of Mexico by this route, rather than continuing down the Mississippi's current channel past
Baton Rouge Baton Rouge ( ; ) is a city in and the capital of the U.S. state of Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-sma ...
and
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
on a longer route to the Gulf. Republished in Although the Red River was once an additional tributary, its water now flows separately into the Gulf of Mexico through the Atchafalaya River.


Watershed

The Mississippi River has the world's fourth-largest
drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...
("watershed" or "catchment"). The basin covers more than , including all or parts of 32 U.S. states and two Canadian provinces. The drainage basin empties into the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...
, 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 The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
,
Mount Elbert Mount Elbert is the highest summit of the Rocky Mountains, the highest point in the U.S. state of Colorado, and the second-highest summit in the contiguous United States (after Mount Whitney). The ultra-prominent fourteener is the highest peak ...
at . In the United States, the Mississippi River drains the majority of the area between the crest of the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
and the crest of the
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
, except for various regions drained to
Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
by the
Red River of the North The Red River (french: rivière Rouge or ) is a river in the north-central United States and central Canada. Originating at the confluence of the Bois de Sioux and Otter Tail rivers between the U.S. states of Minnesota and North Dakota, it fl ...
; to the Atlantic Ocean by the
Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
and the
Saint Lawrence River The St. Lawrence River (french: Fleuve Saint-Laurent, ) is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a (roughly) northeasterly direction, into the Gulf of St. Lawrence, connectin ...
; and to the Gulf of Mexico by the
Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...
, the
Alabama (We dare defend our rights) , anthem = "Alabama (state song), Alabama" , image_map = Alabama in United States.svg , seat = Montgomery, Alabama, Montgomery , LargestCity = Huntsville, Alabama, Huntsville , LargestCounty = Baldwin County, Al ...
and Tombigbee rivers, the
Chattahoochee The Chattahoochee River forms the southern half of the Alabama and Georgia (U.S. state), Georgia border, as well as a portion of the Florida - Georgia border. It is a tributary of the Apalachicola River, a relatively short river formed by the con ...
and Appalachicola rivers, and various smaller coastal waterways along the Gulf. The Mississippi River empties into the Gulf of Mexico about 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 The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
's number is . The retention time from Lake Itasca to the Gulf is typically about 90 days. The
stream gradient Stream gradient (or stream slope) is the grade (or slope) of a stream measured by the ratio of drop in elevation per unit horizontal distance, usually expressed as meters per kilometer or feet per mile. Hydrology and geology A high gradient indicat ...
of the entire river is 0.01%, a drop of 450 m over 3,766 km.


Outflow

The Mississippi River discharges at an annual average rate of between . The Mississippi is the fourteenth largest river in the world by volume. On average, the Mississippi has 8% the flow of the
Amazon River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...
, which moves nearly during wet seasons. Before 1900, the Mississippi River transported an estimated of
sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
per year from the interior of the United States to coastal Louisiana and the Gulf of Mexico. During the last two decades, this number was only per year. The reduction in
sediment transport Sediment transport is the movement of solid particles (sediment), typically due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. Sediment transport occurs in natural system ...
ed down the Mississippi River is the result of engineering modification of the Mississippi, Missouri, and Ohio rivers and their tributaries by dams,
meander cutoff A meander cutoff is a natural form of a cutting or cut in a river occurs when a pronounced meander (hook) in a river is breached by a flow that connects the two closest parts of the hook to form a new channel, a full loop. The steeper drop in grad ...
s, river-training structures, and bank revetments and soil
erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
control programs in the areas drained by them.Meade, R. H., and J. A. Moody, 1984, ''Causes for the decline of suspended-sediment discharge in the Mississippi River system, 1940–2007'' Hydrology Processes vol. 24, pp. 35–49.


Mixing with salt water

Denser salt water from the Gulf of Mexico forms a
salt wedge An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...
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— in 2022—contaminating drinking water supplies and requiring the use of
desalination Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in Soil salinity control, soil desalination, which is an issue f ...
. The
United States Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...
constructed "saltwater sills" or "underwater levees" to contain this 1988, 1999, 2012, and 2022. This consists of 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 The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
's
MODIS The Moderate Resolution Imaging Spectroradiometer (MODIS) is a satellite-based sensor used for earth and climate measurements. There are two MODIS sensors in Earth orbit: one on board the Terra (EOS AM) satellite, launched by NASA in 1999 ...
show a large plume of fresh water, which appears as a dark ribbon against the lighter-blue surrounding waters. These images demonstrate that 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 The Straits of Florida, Florida Straits, or Florida Strait ( es, Estrecho de Florida) is a strait located south-southeast of the North American mainland, generally accepted to be between the Gulf of Mexico and the Atlantic Ocean, and between th ...
, and entered the
Gulf Stream The Gulf Stream, together with its northern extension the North Atlantic Current, North Atlantic Drift, is a warm and swift Atlantic Ocean, Atlantic ocean current that originates in the Gulf of Mexico and flows through the Straits of Florida a ...
. The Mississippi River water rounded the tip of Florida and traveled up the southeast coast to the latitude of
Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
before finally mixing in so thoroughly with the ocean that it could no longer be detected by MODIS.


Course changes

Over geologic time, 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. Through 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
bayou In usage in the Southern United States, a bayou () is a body of water typically found in a flat, low-lying area. It may refer to an extremely slow-moving stream, river (often with a poorly defined shoreline), marshy lake, wetland, or creek. They ...
s. This process has, over the past 5,000 years, caused the coastline of south Louisiana to advance toward the Gulf from . The currently active delta lobe is called the Birdfoot Delta, after its shape, or the Balize Delta, after
La Balize, Louisiana La Balize, Louisiana was a French fort and settlement near the mouth of the Mississippi River, in what later became Plaquemines Parish. The village's name (also spelled La Balise) meant "seamark." La Balize was historically and economically impo ...
, the first French settlement at the mouth of the Mississippi.


Prehistoric courses

The current form of the Mississippi River basin was largely shaped by the
Laurentide Ice Sheet The Laurentide Ice Sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glacial epochs, from 2.58 million years a ...
of the most recent
Ice Age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
. 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 the
Minnesota River The Minnesota River ( dak, Mnísota Wakpá) is a tributary of the Mississippi River, approximately 332 miles (534 km) long, in the U.S. state of Minnesota. It drains a watershed of in Minnesota and about in South Dakota and Iowa. It ris ...
,
James River The James River is a river in the U.S. state of Virginia that begins in the Appalachian Mountains and flows U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 to Chesapea ...
, and Milk River valleys. When the ice sheet completely retreated, many of these "temporary" rivers found paths to
Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
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 The Illinoian Stage is the name used by Quaternary geologists in North America to designate the period c.191,000 to c.130,000 years ago, during the middle Pleistocene, when sediments comprising the Illinoian Glacial Lobe were deposited. It precedes ...
, about 300,000 to 132,000 years before present, blocked 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 The Hennepin Canal State Trail, also just called the Hennepin Canal, is an abandoned waterway in northwest Illinois, between the Mississippi River at Rock Island and the Illinois River near Hennepin. The entire canal is listed on the National ...
roughly follows the ancient channel of the Mississippi downstream from Rock Island to
Hennepin, Illinois Hennepin is a village located on the Illinois River in Putnam County, Illinois, United States. The population was 757 in 2010, an increase of 50 since the 2000 census. It is the county seat and second largest village in Putnam County. Hennepin is ...
. South of Hennepin, to
Alton, Illinois Alton ( ) is a city on the Mississippi River in Madison County, Illinois, United States, about north of St. Louis, Missouri. The population was 25,676 at the 2020 census. It is a part of the River Bend area in the Metro-East region of the ...
, the current
Illinois River The Illinois River ( mia, Inoka Siipiiwi) is a principal tributary of the Mississippi River and is approximately long. Located in the U.S. state of Illinois, it has a drainage basin of . The Illinois River begins at the confluence of the D ...
follows the ancient channel used by the Mississippi River before the Illinoian Stage.McKay, E.D., 2007
''Six Rivers, Five Glaciers, and an Outburst Flood: the Considerable Legacy of the Illinois River.''
(PDF) Proceedings of the 2007 Governor's Conference on the Management of the Illinois River System: Our continuing Commitment, 11th Biennial Conference, Oct. 2–4, 2007, 11 p.
McKay, E.D., and R.C. Berg, 2008

Geological Society of America Abstracts with Programs, Vol. 40, No. 5, p. 78 wit
Powerpoint presentation
Timeline of outflow course changes * c. 5000 BC: The last ice age ended; world sea level became what it is now. * c. 2500 BC:
Bayou Teche Bayou Teche (Louisiana French: ''Bayou Têche'') is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 20, 2011 waterway of great cultural significance in south central Louisiana in t ...
became the main course of the Mississippi. * c. 800 BC: The Mississippi diverted further east. * c. 200 AD:
Bayou Lafourche Bayou Lafourche ( ), originally called Chetimachas River or La Fourche des Chetimaches, (the fork of the Chitimacha), is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 20, 2011 b ...
became the main course of the Mississippi. * c. 1000 AD: The Mississippi's present course took over. * Before c. 1400 AD: The
Red River of the South The Red River, or sometimes the Red River of the South, is a major river in the Southern United States. It was named for its reddish water color from passing through red-bed country in its watershed. It is one of several rivers with that name ...
flowed parallel to the lower Mississippi to the sea * 15th century: Turnbull's Bend in the lower Mississippi extended so far west that it captured the Red River of the South. The Red River below the captured section became the
Atchafalaya River The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
. * 1831: Captain Henry M. Shreve dug a new short course for the Mississippi through the neck of Turnbull's Bend. * 1833 to November 1873: The Great Raft (a huge logjam in the Atchafalaya River) was cleared. The Atchafalaya started to capture the Mississippi and to become its new main lower course. * 1963: The
Old River Control Structure The Old River Control Structure is a floodgate system in a branch of the Mississippi River in central Louisiana. It regulates the flow of water from the Mississippi into the Atchafalaya River, thereby preventing the Mississippi River from chang ...
was completed, controlling how much Mississippi water entered the Atchafalaya.


Historic 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 Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
and separated from the rest of
Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
by the new river channel. Since this event was an avulsion, rather than the effect of incremental erosion and deposition, 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 River, 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 the lower 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 island and community of 14 residents is known as an enclave of Illinois and is accessible only from the Missouri side.


New Madrid Seismic Zone

The New Madrid Seismic Zone, along 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. 1812 New Madrid earthquake, 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 the Midwestern and eastern U.S. These earthquakes created Reelfoot Lake in Tennessee from the altered landscape near the river.


Length

When measured from its traditional source at
Lake Itasca Lake Itasca is a small glacial lake, approximately in area. Located in southeastern Clearwater County, in the Headwaters area of north central Minnesota, it is notable for being the headwater of the Mississippi River. The lake is in Itasca Sta ...
, the Mississippi has a length of . 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 a length of , making it the fourth longest river in the world after the Nile, Amazon River, Amazon, and Yangtze. When measured by the largest stream source (by water volume), the
Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...
, by extension the
Allegheny River The Allegheny River ( ) is a long headwater stream of the Ohio River in western Pennsylvania and New York (state), New York. The Allegheny River runs from its headwaters just below the middle of Pennsylvania's northern border northwesterly into ...
, would be the source, and the Mississippi would begin in Pennsylvania.


Depth

At its source at
Lake Itasca Lake Itasca is a small glacial lake, approximately in area. Located in southeastern Clearwater County, in the Headwaters area of north central Minnesota, it is notable for being the headwater of the Mississippi River. The lake is in Itasca Sta ...
, the Mississippi River is about deep. The average depth of the Mississippi River between Saint Paul and Saint Louis is between deep, the deepest part being
Lake Pepin Lake Pepin is a naturally occurring lake on the Mississippi River on the border between the U.S. states of Minnesota and Wisconsin. It is located in a valley carved by the outflow of an enormous glacial lake at the end of the last Ice Age. The ...
, which averages deep and has a maximum depth of . Between where the Missouri River joins the Mississippi at Saint Louis, Missouri, and Cairo, Illinois, the depth averages . Below Cairo, where the Ohio River joins, the depth averages deep. The deepest part of the river is in New Orleans, where it reaches deep.


Cultural geography


State boundaries

The Mississippi River runs through or along 10 states, from
Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
to
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
, and is used to define portions of these states borders, with
Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
,
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
,
Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to ...
,
Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
, and
Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
along the east side of the river, and
Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...
,
Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
, and
Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
along its west side. Substantial parts of both Minnesota and Louisiana are on either side of 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 the new river channel, contiguous with the adjacent state. Also, due to a meander in the river, a Kentucky Bend, small part of western Kentucky is contiguous with Tennessee but isolated from the rest of its state.


Communities along the river

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. * Bemidji, Minnesota *
Grand Rapids, Minnesota Grand Rapids is a city in Itasca County, Minnesota, United States, and it is the county seat. The population is 11,126 according to the 2020 census. The city is named for the long rapids in the Mississippi River which was the uppermost limit ...
* Jacobson, Minnesota * Palisade, Minnesota * Aitkin, Minnesota * Riverton, Minnesota * Brainerd, Minnesota * Fort Ripley, Minnesota * Little Falls, Minnesota * Sartell, Minnesota * St. Cloud, Minnesota * Monticello, Minnesota * Anoka, Minnesota *
Coon Rapids, Minnesota Coon Rapids is a northern suburb of Minneapolis, and is the largest city in Anoka County, Minnesota, United States. The population was 63,599 at the 2020 census, making it the fifteenth largest city in Minnesota and the seventh largest Twin Ci ...
* Brooklyn Park, Minnesota * Brooklyn Center, Minnesota *
Minneapolis, Minnesota Minneapolis () is the largest city in Minnesota, United States, and the county seat of Hennepin County. The city is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks and waterfalls. Minneapolis has its origins ...
*
Saint Paul, Minnesota Saint Paul (abbreviated St. Paul) is the List of capitals in the United States, capital of the U.S. state of Minnesota and the county seat of Ramsey County, Minnesota, Ramsey County. Situated on high bluffs overlooking a bend in the Mississip ...
* Nininger, Minnesota * Hastings, Minnesota *
Prescott, Wisconsin Prescott is a city in Pierce County, Wisconsin, Pierce County, Wisconsin at the confluence of the St. Croix River (Wisconsin-Minnesota), St. Croix River and Mississippi River. The population was 4,258 at the 2010 census, making it the second-large ...
* Prairie Island Indian Community, Prairie Island, Minnesota * Diamond Bluff, Wisconsin *
Red Wing, Minnesota Red Wing is a city in Goodhue County, Minnesota, Goodhue County, Minnesota, United States, along the upper Mississippi River. The population was 16,547 at the 2020 United States Census, 2020 census. It is the county seat of Goodhue County. This ...
* Hager City, Wisconsin * Maiden Rock, Wisconsin * Stockholm, Wisconsin * Lake City, Minnesota * Maple Springs, Minnesota * Camp Lacupolis, Minnesota * Pepin, Wisconsin * Reads Landing, Minnesota *
Wabasha, Minnesota Wabasha is a city and the county seat of Wabasha County, Minnesota, Wabasha County, Minnesota. The population was 2,559 at the time of the 2020 United States Census, 2020 census. It is on the Mississippi River, near its confluence with the Zumbro ...
* Nelson, Wisconsin * Alma, Wisconsin * Buffalo City, Wisconsin * Weaver, Minnesota * Minneiska, Minnesota * Fountain City, Wisconsin * Winona, Minnesota * Homer, Minnesota * Trempealeau (village), Wisconsin, Trempealeau, Wisconsin * Dakota, Minnesota * Dresbach Township, Winona County, Minnesota, Dresbach, Minnesota * La Crescent, Minnesota *
La Crosse, Wisconsin La Crosse is a city in the U.S. state of Wisconsin and the county seat of La Crosse County. Positioned alongside the Mississippi River, La Crosse is the largest city on Wisconsin's western border. La Crosse's population as of the 2020 census w ...
* Brownsville, Minnesota * Stoddard, Wisconsin * Genoa, Wisconsin * Victory, Wisconsin * Potosi, Wisconsin * De Soto, Wisconsin * Lansing, Iowa * Ferryville, Wisconsin * Lynxville, Wisconsin *
Prairie du Chien, Wisconsin Prairie du Chien () is a city in and the county seat of Crawford County, Wisconsin, United States. The population was 5,506 at the 2020 census. Its ZIP Code is 53821. Often referred to as Wisconsin's second oldest city, Prairie du Chien was esta ...
* Marquette, Iowa * McGregor, Iowa * Wyalusing, Wisconsin * Guttenberg, Iowa * Cassville, Wisconsin *
Dubuque, Iowa Dubuque (, ) is the county seat of Dubuque County, Iowa, United States, located along the Mississippi River. At the time of the 2020 United States Census, 2020 census, the population of Dubuque was 59,667. The city lies at the junction of Iowa, Il ...
* Galena, Illinois * Bellevue, Iowa *
Savanna, Illinois Savanna is a city in Carroll County, Illinois, United States. The population was 2,783 at the 2020 census, down from 2,945 at the 2010 census. Savanna is located along the Mississippi River at the mouth of the Plum River. Going from north to so ...
* Sabula, Iowa * Fulton, Illinois * Clinton, Iowa * Cordova, Illinois * Port Byron, Illinois * LeClaire, Iowa * Rapids City, Illinois * Hampton, Illinois * Bettendorf, Iowa * East Moline, Illinois * Moline, Illinois * Davenport, Iowa * Rock Island, Illinois * Buffalo, Iowa * Muscatine, Iowa * New Boston, Illinois * Keithsburg, Illinois * Oquawka, Illinois *
Burlington, Iowa Burlington is a city in, and the county seat of, Des Moines County, Iowa, United States. The population was 23,982 in the 2020 census, a decline from the 26,839 population in 2000. Burlington is the center of a micropolitan area, which includes ...
* Dallas City, Illinois * Fort Madison, Iowa * Nauvoo, Illinois *
Keokuk, Iowa Keokuk is a city in and a county seat of Lee County, Iowa, United States, along with Fort Madison. It is Iowa's southernmost city. The population was 9,900 at the time of the 2020 census. The city is named after the Sauk chief Keokuk, who is ...
* Warsaw, Illinois * Quincy, Illinois * Hannibal, Missouri * Louisiana, Missouri * Clarksville, Missouri * Grafton, Illinois * Portage Des Sioux, Missouri *
Alton, Illinois Alton ( ) is a city on the Mississippi River in Madison County, Illinois, United States, about north of St. Louis, Missouri. The population was 25,676 at the 2020 census. It is a part of the River Bend area in the Metro-East region of the ...
* St. Louis, St. Louis, Missouri * Ste. Genevieve, Missouri * Kaskaskia, Illinois * Chester, Illinois * Grand Tower, Illinois * Cape Girardeau, Missouri * Thebes, Illinois * Commerce, Missouri *
Cairo, Illinois Cairo ( ) is the southernmost city in Illinois and the county seat of Alexander County. The city is located at the confluence of the Ohio and Mississippi rivers. Fort Defiance, a Civil War camp, was built here in 1862 by Union General Ulysses ...
* Wickliffe, Kentucky * Columbus, Kentucky * Hickman, Kentucky * New Madrid, Missouri * Tiptonville, Tennessee * Caruthersville, Missouri * Osceola, Arkansas * Reverie, Tennessee * Memphis, Tennessee * West Memphis, Arkansas * Tunica, Mississippi * Helena-West Helena, Arkansas * Napoleon, Arkansas (historical) * Arkansas City, Arkansas * Greenville, Mississippi * Mayersville, Mississippi *
Vicksburg, Mississippi Vicksburg is a historic city in Warren County, Mississippi, United States. It is the county seat, and the population at the 2010 census was 23,856. Located on a high bluff on the east bank of the Mississippi River across from Louisiana, Vic ...
* Waterproof, Louisiana * Natchez, Mississippi * Morganza, Louisiana * St. Francisville, Louisiana * New Roads, Louisiana * Baton Rouge, Louisiana * Donaldsonville, Louisiana * Lutcher, Louisiana * Destrehan, Louisiana * New Orleans, New Orleans, Louisiana * Pilottown, Louisiana *
La Balize, Louisiana La Balize, Louisiana was a French fort and settlement near the mouth of the Mississippi River, in what later became Plaquemines Parish. The village's name (also spelled La Balise) meant "seamark." La Balize was historically and economically impo ...
(historical)


Bridge crossings

The road crossing highest on 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 Itasca State Park (pronounced eye-ta-ska) is a state park of Minnesota, United States, and contains the headwaters of the Mississippi River. The park spans of northern Minnesota, and is located about north of Park Rapids, Minnesota and from Ba ...
. 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 the Mississippi River. The first railroad bridge across the Mississippi was built in 1856. It spanned the river between the Rock Island Arsenal in
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
and Davenport, Iowa. Steamboat captains of the day, fearful of competition from the railroads, considered the new bridge a hazard to navigation. Two weeks after the bridge opened, the steamboat ''Effie Afton'' rammed part of the bridge, setting it on fire. Legal proceedings ensued, with Abraham Lincoln defending the railroad. The lawsuit went to the Supreme Court of the United States, which ruled in favor of the railroad. Below is a general overview of selected Mississippi bridges that have notable engineering or landmark significance, with their cities or locations. They are sequenced from the Upper Mississippi's source to the Lower Mississippi's mouth. * Stone Arch Bridge (Minneapolis), Stone Arch BridgeFormer Great Northern Railway (U.S.), Great Northern Railway (now pedestrian) bridge at
Saint Anthony Falls Saint Anthony Falls, or the Falls of Saint Anthony ( dak, italics=no, Owámniyomni, ) located at the northeastern edge of downtown Minneapolis, Minnesota, is the only natural major waterfall on the Mississippi River. Throughout the mid-to-late 1 ...
connecting downtown Minneapolis with the historic Marcy-Holmes neighborhood. * I-35W Saint Anthony Falls BridgeIn Minneapolis, opened in September 2008, replacing the I-35W Mississippi River bridge which had collapsed catastrophically on August 1, 2007, killing 13 and injuring over 100. * Eisenhower Bridge (Mississippi River)In
Red Wing, Minnesota Red Wing is a city in Goodhue County, Minnesota, Goodhue County, Minnesota, United States, along the upper Mississippi River. The population was 16,547 at the 2020 United States Census, 2020 census. It is the county seat of Goodhue County. This ...
, opened by Dwight D. Eisenhower in November 1960. * I-90 Mississippi River BridgeConnects
La Crosse, Wisconsin La Crosse is a city in the U.S. state of Wisconsin and the county seat of La Crosse County. Positioned alongside the Mississippi River, La Crosse is the largest city on Wisconsin's western border. La Crosse's population as of the 2020 census w ...
, and Winona County, Minnesota, located just south of Lock and Dam No. 7. * Black Hawk BridgeConnects Lansing, Iowa, Lansing in Allamakee County, Iowa and rural Crawford County, Wisconsin; locally referred to as the Lansing Bridge and documented in the Historic American Buildings Survey, Historic American Engineering Record. * Dubuque-Wisconsin BridgeConnects
Dubuque, Iowa Dubuque (, ) is the county seat of Dubuque County, Iowa, United States, located along the Mississippi River. At the time of the 2020 United States Census, 2020 census, the population of Dubuque was 59,667. The city lies at the junction of Iowa, Il ...
, and Grant County, Wisconsin. * Julien Dubuque BridgeJoins the cities of
Dubuque, Iowa Dubuque (, ) is the county seat of Dubuque County, Iowa, United States, located along the Mississippi River. At the time of the 2020 United States Census, 2020 census, the population of Dubuque was 59,667. The city lies at the junction of Iowa, Il ...
, and East Dubuque, Illinois; listed in the National Register of Historic Places. * Savanna-Sabula BridgeA truss bridge and causeway connecting the city of
Savanna, Illinois Savanna is a city in Carroll County, Illinois, United States. The population was 2,783 at the 2020 census, down from 2,945 at the 2010 census. Savanna is located along the Mississippi River at the mouth of the Plum River. Going from north to so ...
, and the island city of Sabula, Iowa. The bridge carries U.S. Highway 52 over the river, and is the terminus of both Iowa Highway 64 and Illinois Route 64. Added to the National Register of Historic Places in 1999. * Fred Schwengel Memorial BridgeA 4-lane steel girder bridge that carries Interstate 80 and connects LeClaire, Iowa, and Rapids City, Illinois. Completed in 1966. * Clinton Railroad BridgeA swing bridge that connects Clinton, Iowa and Fulton, Illinois, Fulton (Albany, Illinois, Albany),
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
. Known as the Chicago and Northwestern Railroad Bridge. * I-74 BridgeConnects Bettendorf, Iowa, and Moline, Illinois; originally known as the ''Iowa-Illinois Memorial Bridge''. * Government BridgeConnects Rock Island, Illinois and Davenport, Iowa, adjacent to Lock and Dam No. 15; the fourth crossing in this vicinity, built in 1896. * Rock Island Centennial BridgeConnects Rock Island, Illinois, and Davenport, Iowa; opened in 1940. * Sergeant John F. Baker, Jr. BridgeConnects Rock Island, Illinois, and Davenport, Iowa; opened in 1973. * Norbert F. Beckey BridgeConnects Muscatine, Iowa, and Rock Island County, Illinois; became first U.S. bridge to be illuminated with light-emitting diode (LED) lights decoratively illuminating the facade of the bridge. * Great River BridgeA cable-stayed bridge connecting Burlington, Iowa, to Gulf Port, Illinois. * Fort Madison Toll BridgeConnects Fort Madison, Iowa, and unincorporated Niota, Illinois; also known as the ''Santa Fe Swing Span Bridge''; at the time of its construction the longest and heaviest electrified swing span on the Mississippi River. Listed in the National Register of Historic Places since 1999. * Keokuk–Hamilton BridgeConnects
Keokuk, Iowa Keokuk is a city in and a county seat of Lee County, Iowa, United States, along with Fort Madison. It is Iowa's southernmost city. The population was 9,900 at the time of the 2020 census. The city is named after the Sauk chief Keokuk, who is ...
and Hamilton, Illinois; opened in 1985 replacing an older bridge which is still in use as a railroad bridge. * Bayview BridgeA cable-stayed bridge bringing westbound U.S. Highway 24 over the river, connecting the cities of West Quincy, Missouri, and Quincy, Illinois. * Quincy Memorial BridgeConnects the cities of West Quincy, Missouri, and Quincy, Illinois, carrying eastbound U.S. 24, the older of these two U.S. 24 bridges. * Clark BridgeA cable-stayed bridge connecting West Alton, Missouri, and
Alton, Illinois Alton ( ) is a city on the Mississippi River in Madison County, Illinois, United States, about north of St. Louis, Missouri. The population was 25,676 at the 2020 census. It is a part of the River Bend area in the Metro-East region of the ...
, also known as the ''Super Bridge'' as the result of an appearance on the PBS program, ''Nova (American TV series), Nova''; built in 1994, carrying U.S. Route 67 across the river. This is the northernmost river crossing in the St. Louis metropolitan area, replacing the ''Old Clark Bridge'', a truss bridge built in 1928, named after explorer William Clark (explorer), William Clark. * Chain of Rocks BridgeLocated on the northern edge of St. Louis, notable for a 22-degree bend occurring at the middle of the crossing, necessary for navigation on the river; formerly used by U.S. Route 66 to cross the Mississippi. Replaced for road traffic in 1966 by New Chain of Rocks Bridge, a nearby pair of new bridges; now a pedestrian bridge. * Eads BridgeA combined road and railway bridge, connecting St. Louis and East St. Louis, Illinois. When completed in 1874, it was the longest arch bridge in the world, with an overall length of . The three ribbed steel arch spans were considered daring, as was the use of steel as a primary structural material; it was the first such use of true steel in a major bridge project. * Chester BridgeA truss bridge connecting Route 51 (Missouri), Route 51 in Missouri with Illinois Route 150, between Perryville, Missouri, and Chester, Illinois. The bridge can be seen at the beginning of the 1967 film ''In the Heat of the Night (film), In the Heat of the Night''. In the 1940s, the main span was destroyed by a tornado. * Bill Emerson Memorial Bridge—Connecting Cape Girardeau, Missouri and East Cape Girardeau, Illinois, completed in 2003 and illuminated by 140 lights. * Caruthersville Bridge A single tower cantilever bridge carrying Interstate 155 (Missouri–Tennessee), Interstate 155 and U.S. Route 412 across the Mississippi River between Caruthersville, Missouri and Dyersburg, Tennessee. * Hernando de Soto BridgeA through arch bridge carrying Interstate 40 across the Mississippi between West Memphis, Arkansas, and Memphis, Tennessee. * Harahan BridgeA Cantilever bridge, cantilevered truss bridge, through truss bridge, carrying two rail lines of the Union Pacific Railroad across the river between West Memphis, Arkansas, and Memphis, Tennessee. * Frisco BridgeA Cantilever bridge, cantilevered truss bridge, through truss bridge, carrying a rail line across the river between West Memphis, Arkansas, and Memphis, Tennessee, previously known as the ''Memphis Bridge''. When it opened on May 12, 1892, it was the first crossing of the Lower Mississippi and the longest span in the U.S. Listed as a List of historic civil engineering landmarks, Historic Civil Engineering Landmark. * Memphis & Arkansas BridgeA cantilever bridge, cantilevered truss bridge, through truss bridge, carrying Interstate 55 between Memphis and West Memphis; listed on the National Register of Historic Places. * Helena Bridge * Greenville Bridge * Old Vicksburg Bridge * Vicksburg Bridge * Natchez-Vidalia Bridge * John James Audubon Bridge (Mississippi River), John James Audubon BridgeThe second-longest cable-stayed bridge in the Western Hemisphere; connects Pointe Coupee Parish, Louisiana, Pointe Coupee and West Feliciana Parish, Louisiana, West Feliciana Parishes in Louisiana. It is the only crossing between Baton Rouge and Natchez. This bridge was opened a month ahead of schedule in May 2011, due to the 2011 Mississippi River floods, 2011 floods. * Huey P. Long Bridge (Baton Rouge), Huey P. Long BridgeA truss cantilever bridge carrying U.S. Route 190, US 190 (Airline Highway) and one rail line between East Baton Rouge Parish, Louisiana, East Baton Rouge and West Baton Rouge Parish, Louisiana, West Baton Rouge Parishes in Louisiana. * Horace Wilkinson BridgeA cantilever bridge, cantilevered truss bridge, through truss bridge, carrying six lanes of Interstate 10 between Baton Rouge, Louisiana, Baton Rouge and Port Allen, Louisiana, Port Allen in Louisiana. It is the highest bridge over the Mississippi River. * Sunshine Bridge * Gramercy Bridge * Hale Boggs Memorial Bridge * Huey P. Long Bridge (Jefferson Parish), Huey P. Long BridgeIn Jefferson Parish, Louisiana, the first Mississippi River span built in Louisiana. * Crescent City ConnectionConnects the east and west banks of
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
, Louisiana; the fifth-longest cantilever bridge in the world.


Navigation and flood control

A clear channel is needed for the
barge Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels ...
s and other vessels that make the main stem Mississippi one of the great commercial waterways of the world. The task of maintaining a navigation channel is the responsibility of the
United States Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...
, which was established in 1802. Earlier projects began as early as 1829 to remove snags, close off secondary channels and excavate rocks and Shoal, sandbars. A series of 29 Lock (water transport), locks and dams on the upper Mississippi, most of which were built in the 1930s, is designed primarily to maintain a channel for commercial barge traffic. The lakes formed are also used for recreational boating and fishing. The dams make the river deeper and wider but do not stop it. No flood control is intended. During periods of high flow, the gates, some of which are submersible, are completely opened and the dams simply cease to function. Below St. Louis, the Mississippi is relatively free-flowing, although it is constrained by numerous levees and directed by numerous wing dams. The scope and scale of the levees, built along either side of the river to keep it on its course, has often been compared to the Great Wall of China. On the lower Mississippi, from Baton Rouge, Louisiana, Baton Rouge to the mouth of the Mississippi, the navigation depth is , allowing container ships and cruise ships to dock at the Port of New Orleans and bulk cargo ships shorter than air draft that fit under the Huey P. Long Bridge (Jefferson Parish), Huey P. Long Bridge to traverse the Mississippi to Baton Rouge. There is a feasibility study to dredge this portion of the river to to allow New Panamax ship depths.


19th century

In 1829, there were surveys of the two major obstacles on the upper Mississippi, the Des Moines Rapids and the Rock Island Rapids, where the river was shallow and the riverbed was rock. The Des Moines Rapids were about long and just above the mouth of the
Des Moines River The Des Moines River () is a tributary of the Mississippi River in the upper Midwestern United States that is approximately long from its farther headwaters.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe Na ...
at Keokuk, Iowa. The Rock Island Rapids were between Rock Island, Illinois, Rock Island and Moline, Illinois. Both rapids were considered virtually impassable. In 1848, the Illinois and Michigan Canal was built to connect the Mississippi River to Lake Michigan via the Illinois River near Peru, Illinois. The canal allowed shipping between these important waterways. In 1900, the canal was replaced by the Chicago Sanitary and Ship Canal. The second canal, in addition to shipping, also allowed Chicago to address specific health issues (typhoid fever, cholera and other waterborne diseases) by sending its waste down the Illinois and Mississippi river systems rather than polluting its water source of Lake Michigan. The Corps of Engineers recommended the excavation of a channel at the Des Moines Rapids, but work did not begin until after Lieutenant Robert E. Lee endorsed the project in 1837. The Corps later also began excavating the Rock Island Rapids. By 1866, it had become evident that excavation was impractical, and it was decided to build a canal around the Des Moines Rapids. The canal opened in 1877, but the Rock Island Rapids remained an obstacle. In 1878, Congress authorized the Corps to establish a channel to be obtained by building wing dams that direct the river to a narrow channel causing it to cut a deeper channel, by closing secondary channels and by dredging. The channel project was complete when the Moline Lock, which bypassed the Rock Island Rapids, opened in 1907. To improve navigation between St. Paul, Minnesota, and
Prairie du Chien, Wisconsin Prairie du Chien () is a city in and the county seat of Crawford County, Wisconsin, United States. The population was 5,506 at the 2020 census. Its ZIP Code is 53821. Often referred to as Wisconsin's second oldest city, Prairie du Chien was esta ...
, the Corps constructed several dams on lakes in the headwaters area, including
Lake Winnibigoshish Lake Winnibigoshish is a body of water in north central Minnesota in the Chippewa National Forest. Its name comes from the Ojibwe language ''Wiinibiigoonzhish'', a diminutive and pejorative form of ''Wiinibiig'', meaning "filthy water" (i.e., "br ...
and Pokegama Dam, Lake Pokegama. The dams, which were built beginning in the 1880s, stored spring run-off which was released during low water to help maintain channel depth.


20th century

In 1907, Congress authorized a channel project on the Mississippi River, which was not complete when it was abandoned in the late 1920s in favor of the channel project. In 1913, construction was complete on Lock and Dam No. 19 at
Keokuk, Iowa Keokuk is a city in and a county seat of Lee County, Iowa, United States, along with Fort Madison. It is Iowa's southernmost city. The population was 9,900 at the time of the 2020 census. The city is named after the Sauk chief Keokuk, who is ...
, the first dam below St. Anthony Falls. Built by a private power company (Union Electric Company of St. Louis) to generate electricity (originally for streetcars in St. Louis), the Keokuk dam was one of the largest hydro-electric plants in the world at the time. The dam also eliminated the Des Moines Rapids. Lock and Dam No. 1, Mississippi River, Lock and Dam No. 1 was completed in Minneapolis, Minnesota in 1917. Lock and Dam No. 2, near Hastings, Minnesota, was completed in 1930. Before the Great Mississippi Flood of 1927, the Corps's primary strategy was to close off as many side channels as possible to increase the flow in the main river. It was thought that the river's velocity would scour off bottom
sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
s, deepening the river and decreasing the possibility of flooding. The 1927 flood proved this to be so wrong that communities threatened by the flood began to create their own levee breaks to relieve the force of the rising river. The Rivers and Harbors Act of 1930 authorized the channel project, which called for a navigation channel feet deep and wide to accommodate multiple-barge tows. This was achieved by a series of locks and dams, and by dredging. Twenty-three new locks and dams were built on the upper Mississippi in the 1930s in addition to the three already in existence. Until the 1950s, there was no dam below Lock and Dam 26 at Alton, Illinois. Chain of Rocks Lock (Lock and Dam No. 27), which consists of a low-water dam and an canal, was added in 1953, just below the confluence with the Missouri River, primarily to bypass a series of rock ledges at St. Louis. It also serves to protect the St. Louis city water intakes during times of low water. U.S. government scientists determined in the 1950s that the Mississippi River was starting to switch to the Atchafalaya River channel because of its much steeper path to the Gulf of Mexico. Eventually, the Atchafalaya River would capture the Mississippi River and become its main channel to the Gulf of Mexico, leaving New Orleans on a side channel. As a result, the United States Congress, U.S. Congress authorized a project called the
Old River Control Structure The Old River Control Structure is a floodgate system in a branch of the Mississippi River in central Louisiana. It regulates the flow of water from the Mississippi into the Atchafalaya River, thereby preventing the Mississippi River from chang ...
, which has prevented the Mississippi River from leaving its current channel that drains into the Gulf via New Orleans. Because the large scale of high-energy water flow threatened to damage the structure, an auxiliary flow control station was built adjacent to the standing control station. This $300 million project was completed in 1986 by the Corps of Engineers. Beginning in the 1970s, the Corps applied hydrological transport models to analyze flood flow and water quality of the Mississippi. Dam 26 at Alton, Illinois, which had structural problems, was replaced by the Mel Price Lock and Dam in 1990. The original Lock and Dam 26 was demolished.


21st century

The Corps now actively creates and maintains spillways and floodways to divert periodic water surges into backwater channels and lakes, as well as route part of the Mississippi's flow into the Atchafalaya Basin and from there to the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...
, bypassing
Baton Rouge Baton Rouge ( ; ) is a city in and the capital of the U.S. state of Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-sma ...
and
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
. The main structures are the Birds Point-New Madrid Floodway in Missouri; the
Old River Control Structure The Old River Control Structure is a floodgate system in a branch of the Mississippi River in central Louisiana. It regulates the flow of water from the Mississippi into the Atchafalaya River, thereby preventing the Mississippi River from chang ...
and the Morganza Spillway in Louisiana, which direct excess water down the west and east sides (respectively) of the
Atchafalaya River The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
; and the Bonnet Carré Spillway, also in Louisiana, which directs floodwaters to Lake Pontchartrain (see diagram). Some experts blame urban sprawl for increases in both the risk and frequency of flooding on the Mississippi River. Some of the pre-1927 strategy remains in use today, with the Corps actively cutting the necks of meander, horseshoe bends, allowing the water to move faster and reducing flood heights.


History

Approximately 50,000 years ago, the Central United States was covered by an inland sea, which was drained by the Mississippi and its tributaries into the Gulf of Mexico—creating large floodplains and extending the continent further to the south in the process. The soil in areas such as Louisiana was thereafter found to be very rich.


Native Americans

The area of the Mississippi River basin was first Prehistoric migration and settlement of the Americas from Asia, settled by Hunter-gatherer, hunting and gathering Native Americans in the United States, Native American peoples and is considered one of the few independent centers of Domestication of plants, plant domestication in human history. Evidence of early Plant cultivation, cultivation of Helianthus annuus, sunflower, a Chenopodium berlandieri, goosefoot, a Iva annua, marsh elder and an indigenous squash (plant), squash dates to the 4th millennium BC. The lifestyle gradually became more settled after around 1000 BC during what is now called the Woodland period, with increasing evidence of shelter construction, Ceramics of indigenous peoples of the Americas, pottery, weaving and other practices. A network of trade routes referred to as the Hopewell tradition, Hopewell interaction sphere was active along the waterways between about 200 and 500 AD, spreading common cultural practices over the entire area between the Gulf of Mexico and the Great Lakes. A period of more isolated communities followed, and agriculture introduced from Mesoamerica based on the Three Sisters (agriculture), Three Sisters (maize, beans and squash) gradually came to dominate. After around 800 AD there arose an advanced agricultural society today referred to as the Mississippian culture, with evidence of highly Social stratification, stratified complex society, complex chiefdoms and large human settlement, population centers. The most prominent of these, now called Cahokia, was occupied between about 600 and 1400 AD and at its peak numbered between 8,000 and 40,000 inhabitants, larger than London, England of that time. At the time of first contact with Europeans, Cahokia and many other Mississippian cities had dispersed, and archaeology, archaeological finds attest to increased social stress. Modern American Indian nations inhabiting the Mississippi basin include Cheyenne, Sioux, Ojibwe, Potawatomi, Ho-Chunk, Fox (tribe), Fox, Kickapoo people, Kickapoo, Tamaroa (tribe), Tamaroa, Moingwena, Quapaw and Chickasaw. The word ''Mississippi'' itself comes from ''Messipi'', the French rendering of the Ojibwe language, Anishinaabe (Ojibwe or Algonquin) name for the river, ''Misi-ziibi'' (Great River). The Ojibwe called Lake Itasca ''Omashkoozo-zaaga'igan'' (Elk Lake) and the river flowing out of it ''Omashkoozo-ziibi'' (Elk River). After flowing into Lake Bemidji, the Ojibwe called the river ''Bemijigamaag-ziibi'' (River from the Traversing Lake). After flowing into Cass Lake (Minnesota), Cass Lake, the name of the river changes to ''Gaa-miskwaawaakokaag-ziibi'' (Red Cedar River) and then out of
Lake Winnibigoshish Lake Winnibigoshish is a body of water in north central Minnesota in the Chippewa National Forest. Its name comes from the Ojibwe language ''Wiinibiigoonzhish'', a diminutive and pejorative form of ''Wiinibiig'', meaning "filthy water" (i.e., "br ...
as ''Wiinibiigoonzhish-ziibi'' (Miserable Wretched Dirty Water River), ''Gichi-ziibi'' (Big River) after the confluence with the Leech Lake River, then finally as ''Misi-ziibi'' (Great River) after the confluence with the Crow Wing River. After the expeditions by Giacomo Beltrami and Henry Schoolcraft, the longest stream above the juncture of the Crow Wing River and ''Gichi-ziibi'' was named "Mississippi River". The Mississippi River Band of Chippewa Indians, known as the ''Gichi-ziibiwininiwag'', are named after the stretch of the Mississippi River known as the ''Gichi-ziibi''. The Cheyenne, one of the earliest inhabitants of the upper Mississippi River, called it the ''Máʼxe-éʼometaaʼe'' (Big Greasy River) in the Cheyenne language. The Arapaho language, Arapaho name for the river is ''Beesniicíe''. The Pawnee language, Pawnee name is ''Kickaátit''. The Mississippi was spelled during French Louisiana and was also known as the Rivière Saint-Louis.


European exploration

In 1519 Spanish explorer Alonso Álvarez de Pineda became the first recorded European to reach the Mississippi River, followed by Hernando de Soto who reached the river on May 8, 1541, and called it ''Río del Espíritu Santo'' ("River of the Holy Spirit"), in the area of what is now Mississippi. In Spanish, the river is called ''Río Mississippi''. French explorers Louis Jolliet and Jacques Marquette began exploring the Mississippi in the 17th century. Marquette traveled with a Sioux Indian who named it ''Ne Tongo'' ("Big river" in Sioux language) in 1673. Marquette proposed calling it the ''River of the Immaculate Conception''. When Louis Jolliet explored the Mississippi Valley in the 17th century, natives guided him to a quicker way to return to French Canada via the Illinois River. When he found the Chicago Portage, he remarked that a canal of "only half a League (unit), league" (less than ) would join the Mississippi and the Great Lakes. In 1848, the continental divide separating the waters of the Great Lakes and the Mississippi Valley was breached by the Illinois and Michigan canal via the Chicago River. This both accelerated the development, and forever changed the ecology of the Mississippi Valley and the Great Lakes. In 1682, René-Robert Cavelier, Sieur de La Salle and Henri de Tonti claimed the entire Mississippi River valley for France, calling the river ''Colbert River'' after Jean-Baptiste Colbert and the region ''Louisiana (New France), La Louisiane'', for Louis XIV of France, King Louis XIV. On March 2, 1699, Pierre Le Moyne d'Iberville rediscovered the mouth of the Mississippi, following the death of La Salle."Pierre Le Moyne, Sieur d'Iberville" (bio), webpage from ''The Catholic Encyclopedia'', Volume VII, 1910, New York
CathEn-07614b
.
The French built the small fort of La Balize, Louisiana, La Balise there to control passage. In 1718, about upriver, New Orleans was established along the river crescent by Jean-Baptiste Le Moyne, Sieur de Bienville, with construction patterned after the 1711 resettlement on Mobile Bay of Mobile, Alabama, Mobile, the capital of French Louisiana at the time. In 1727, Étienne Perier (governor), Étienne Perier begins work, using enslaved African laborers, on the first
levee A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...
s on the Mississippi River.


Colonization

Following Great Britain in the Seven Years War, Britain's victory in the Seven Years War, the Mississippi became the border between the British and Spanish Empires. The Treaty of Paris (1763) gave Kingdom of Great Britain, Great Britain rights to all land east of the Mississippi and Spain rights to land west of the Mississippi. Spain also ceded Spanish Florida, Florida to Britain to regain Cuba, which the British occupied during the war. Britain then divided the territory into East Florida, East and West Florida. Article 8 of the Treaty of Paris (1783) states, "The navigation of the river Mississippi, from its source to the ocean, shall forever remain free and open to the subjects of Great Britain and the citizens of the United States". With this treaty, which ended the American Revolutionary War, Britain also ceded West Florida back to Spain to regain the Bahamas, which Spain had occupied during the war. Initial disputes around the ensuing claims of the U.S. and Spain were resolved when Spain was pressured into signing Pinckney's Treaty in 1795. However, in 1800, under duress from Napoleon of France, Spain ceded an undefined portion of West Florida to France in the secret Third Treaty of San Ildefonso, Treaty of San Ildefonso. The United States then secured effective control of the river when it bought the Louisiana Territory from France in the Louisiana Purchase of 1803. This triggered a dispute between Spain and the U.S. on which parts of West Florida Spain had ceded to France in the first place, which would decide which parts of West Florida the U.S. had bought from France in the Louisiana Purchase, versus which were unceded Spanish property. Due to ongoing U.S. colonization creating facts on the ground, and U.S. military actions, Spain ceded both West and East Florida in their entirety to the United States in the Adams–Onís Treaty of 1819. The last serious European challenge to U.S. control of the river came at the conclusion of the War of 1812, when British forces mounted an attack on
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
just 15 days after the signing of the Treaty of Ghent. The attack Battle of New Orleans, was repulsed by an American army under the command of General Andrew Jackson. In the Treaty of 1818, the U.S. and Great Britain agreed to fix the border running from the Lake of the Woods to the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
along the 49th parallel north. In effect, the U.S. ceded the northwestern extremity of the Mississippi basin to the British in exchange for the southern portion of the Red River of the North, Red River basin. So many settlers traveled westward through the Mississippi river basin, as well as settled in it, that Zadok Cramer wrote a guidebook called ''The Navigator (1801 guide book), The Navigator'', detailing the features, dangers, and navigable waterways of the area. It was so popular that he updated and expanded it through 12 editions over 25 years. The colonization of the area was barely slowed by the three 1812 New Madrid earthquake, earthquakes in 1811 and 1812, estimated at 8 on the Richter magnitude scale, that were centered near New Madrid, Missouri.


Steamboat era

Mark Twain's book, ''Life on the Mississippi'', covered the steamboat commerce, which took place from 1830 to 1870, before more modern ships replaced the steamer. ''Harper's Weekly'' first published the book as a seven-part Serial (publishing), serial in 1875. James R. Osgood & Company published the full version, including a passage from the then unfinished ''Adventures of Huckleberry Finn'' and works from other authors, in 1885. The first steamboat to travel the full length of the Lower Mississippi from the Ohio River to New Orleans was the ''New Orleans (steamboat), New Orleans'' in December 1811. Its maiden voyage occurred during the series of 1812 New Madrid earthquake, New Madrid earthquakes in 1811–12. The Upper Mississippi was treacherous, unpredictable and to make traveling worse, the area was not properly mapped out or surveyed. Until the 1840s, only two trips a year to the Twin Cities landings were made by steamboats, which suggests it was not very profitable. Steamboat transport remained a viable industry, both in terms of passengers and freight, until the end of the first decade of the 20th century. Among the several Mississippi River system steamboat companies was the noted Anchor Line (riverboat company), Anchor Line, which, from 1859 to 1898, operated a luxurious fleet of steamers between St. Louis and New Orleans. Italian explorer Giacomo Beltrami wrote about his journey on the ''Virginia'', which was the first steamboat to make it to Fort St. Anthony in Minnesota. He referred to his voyage as a promenade that was once a journey on the Mississippi. The steamboat era changed the economic and political life of the Mississippi, as well as of travel itself. The Mississippi was completely changed by the steamboat era as it transformed into a flourishing tourist trade.


Civil War

Control of the river was a strategic objective of both sides in the
American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...
, forming a part of the U.S. Anaconda Plan. In 1862,
Union Union commonly refers to: * Trade union, an organization of workers * Union (set theory), in mathematics, a fundamental operation on sets Union may also refer to: Arts and entertainment Music * Union (band), an American rock group ** ''Un ...
forces coming down the river successfully cleared Confederate defenses at Battle of Island Number Ten, Island Number 10 and Memphis, Tennessee, while Naval forces coming upriver from the Gulf of Mexico captured New Orleans, Louisiana. One of the last major Confederate strongholds was on the heights overlooking the river at
Vicksburg, Mississippi Vicksburg is a historic city in Warren County, Mississippi, United States. It is the county seat, and the population at the 2010 census was 23,856. Located on a high bluff on the east bank of the Mississippi River across from Louisiana, Vic ...
; the Union's Vicksburg Campaign (December 1862–July 1863), and the fall of Port Hudson, Louisiana, Port Hudson, completed control of the lower Mississippi River. The Union victory ended the Siege of Vicksburg on July 4, 1863, and was pivotal to the Union's final victory of the Civil War.


20th and 21st centuries

The "Big Freeze" of 1918–19 blocked river traffic north of Memphis, Tennessee, preventing transportation of coal from southern Illinois. This resulted in widespread shortages, high prices, and rationing of coal in January and February. In the spring of 1927, the river broke out of its banks in 145 places, during the Great Mississippi Flood of 1927 and inundated to a depth of up to . In 1930, Fred Newton (swimmer), Fred Newton was the first person to swim the length of the river, from Minneapolis to New Orleans. The journey took 176 days and covered 1,836 miles. In 1962 and 1963, industrial accidents spilled of soybean oil into the Mississippi and Minnesota River, Minnesota rivers. The oil covered the Mississippi River from St. Paul to Lake Pepin, creating an ecological disaster and a demand to control water pollution. On October 20, 1976, the automobile ferry, ''MV George Prince ferry disaster, MV George Prince'', was struck by a ship traveling upstream as the ferry attempted to cross from Destrehan, Louisiana, to Luling, Louisiana. Seventy-eight passengers and crew died; only eighteen survived the accident. In 1988, the water level of the Mississippi fell to below zero on the Memphis gauge. The remains of wooden-hulled water craft were exposed in an area of on the bottom of the Mississippi River at West Memphis, Arkansas. They dated to the late 19th to early 20th centuries. The State of Arkansas, the Arkansas Archeological Survey, and the Arkansas Archeological Society responded with a two-month data recovery effort. The fieldwork received national media attention as good news in the middle of a drought. The Great Mississippi and Missouri Rivers Flood of 1993, Great Flood of 1993 was another significant flood, primarily affecting the Mississippi above its confluence with the Ohio River at Cairo, Illinois. Two portions of the Mississippi were designated as American Heritage Rivers in 1997: the lower portion around Louisiana and Tennessee, and the upper portion around Iowa, Illinois, Minnesota, Missouri and Wisconsin. The Nature Conservancy's project called "America's Rivershed Initiative" announced a 'report card' assessment of the entire basin in October 2015 and gave the grade of D+. The assessment noted the aging navigation and flood control infrastructure along with multiple environmental problems. In 2002, Slovenian long-distance swimmer Martin Strel swam the entire length of the river, from Minnesota to Louisiana, over the course of 68 days. In 2005, the Source to Sea Expedition paddled the Mississippi and
Atchafalaya River The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
s to benefit the Audubon Society's Upper Mississippi River Campaign.


Future

Geologists believe that the lower Mississippi could take a new course to the Gulf. Either of two new routes—through the Atchafalaya Basin or through Lake Pontchartrain—might become the Mississippi's main channel if flood-control structures are overtopped or heavily damaged during a severe flood. Failure of the
Old River Control Structure The Old River Control Structure is a floodgate system in a branch of the Mississippi River in central Louisiana. It regulates the flow of water from the Mississippi into the Atchafalaya River, thereby preventing the Mississippi River from chang ...
, the Morganza Spillway, or nearby levees would likely re-route the main channel of the Mississippi through Louisiana, Louisiana's Atchafalaya Basin and down the
Atchafalaya River The Atchafalaya River ( french: La Rivière Atchafalaya, es, Río Atchafalaya) is a distributary of the Mississippi River and Red River in south central Louisiana in the United States. It flows south, just west of the Mississippi River, and ...
to reach the Gulf of Mexico south of Morgan City, Louisiana, Morgan City in southern Louisiana. This route provides a more direct path to the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...
than the present Mississippi River channel through Baton Rouge, Louisiana, Baton Rouge and
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
. While the risk of such a diversion is present during any major flood event, such a change has so far been prevented by active human intervention involving the construction, maintenance, and operation of various levees, spillways, and other control structures by the U.S. Army Corps of Engineers. The Old River Control Structure, between the present Mississippi River channel and the Atchafalaya Basin, sits at the normal water elevation and is ordinarily used to divert 30% of the Mississippi flow to the Atchafalaya River. There is a steep drop here away from the Mississippi's main channel into the Atchafalaya Basin. If this facility were to fail during a major flood, there is a strong concern the water would Bridge scour, scour and erode the river bottom enough to capture the Mississippi's main channel. The structure was nearly lost during the 1973 Mississippi River floods, 1973 flood, but repairs and improvements were made after engineers studied the forces at play. In particular, the Corps of Engineers made many improvements and constructed additional facilities for routing water through the vicinity. These additional facilities give the Corps much more flexibility and potential flow capacity than they had in 1973, which further reduces the risk of a catastrophic failure in this area during other major floods, such as that of 2011 Mississippi River floods, 2011. Because the Morganza Spillway is slightly higher and well back from the river, it is normally dry on both sides. Even if it failed at the crest during a severe flood, the floodwaters would have to erode to normal water levels before the Mississippi could permanently jump channel at this location. During the 2011 floods, the Corps of Engineers opened the Morganza Spillway to 1/4 of its capacity to allow of water to flood the Morganza and Atchafalaya floodways and continue directly to the Gulf of Mexico, bypassing Baton Rouge and New Orleans.Estimated Inundation
(US Army Corps of Engineers)
In addition to reducing the Mississippi River crest downstream, this diversion reduced the chances of a channel change by reducing stress on the other elements of the control system. Some geologists have noted that the possibility for course change into the Atchafalaya also exists in the area immediately north of the Old River Control Structure. Army Corps of Engineers geologist Fred Smith once stated, "The Mississippi wants to go west. 1973 was a forty-year flood. The big one lies out there somewhere—when the structures can't release all the floodwaters and the levee is going to have to give way. That is when the river's going to jump its banks and try to break through." Another possible course change for the Mississippi River is a diversion into Lake Pontchartrain near
New Orleans New Orleans ( , ,New Orleans
Merriam-Webster.
; french: La Nouvelle-Orléans , es, Nuev ...
. This route is controlled by the Bonnet Carré Spillway, built to reduce flooding in New Orleans. This spillway and an imperfect natural levee about high are all that prevents the Mississippi from taking a new, shorter course through Lake Pontchartrain to the Gulf of Mexico. Diversion of the Mississippi's main channel through Lake Pontchartrain would have consequences similar to an Atchafalaya diversion, but to a lesser extent, since the present river channel would remain in use past Baton Rouge and into the New Orleans area.


Recreation

The sport of waterskiing, water skiing was invented on the river in a wide region between Minnesota and Wisconsin known as
Lake Pepin Lake Pepin is a naturally occurring lake on the Mississippi River on the border between the U.S. states of Minnesota and Wisconsin. It is located in a valley carved by the outflow of an enormous glacial lake at the end of the last Ice Age. The ...
. Ralph Samuelson of Lake City, Minnesota, created and refined his skiing technique in late June and early July 1922. He later performed the first water ski jump in 1925 and was pulled along at by a Curtiss flying boat later that year. There are seven National Park Service sites along the Mississippi River. The Mississippi National River and Recreation Area is the National Park Service site dedicated to protecting and interpreting the Mississippi River itself. The other six National Park Service sites along the river are (listed from north to south): * Effigy Mounds National Monument * Gateway Arch National Park (includes
Gateway Arch The Gateway Arch is a monument in St. Louis, Missouri, United States. Clad in stainless steel and built in the form of a weighted catenary arch, it is the world's tallest arch and Missouri's tallest accessible building. Some sources conside ...
) * Vicksburg National Military Park * Natchez National Historical Park * New Orleans Jazz National Historical Park * Jean Lafitte National Historical Park and Preserve


Ecology

The Mississippi basin is home to a highly diverse aquatic fauna and has been called the "mother fauna" of North American freshwater.


Fish

About 375 fish species are known from the Mississippi basin, far exceeding other North Hemisphere river basins exclusively within temperate/subtropical regions, except the Yangtze. Within the Mississippi basin, streams that have their source in the Appalachian and Ozark highlands contain especially many species. Among the fish species in the basin are numerous endemics, as well as Relict (biology), relicts such as American paddlefish, paddlefish, sturgeon, gar and bowfin. Because of its size and high species diversity, the Mississippi basin is often divided into subregions. The Upper Mississippi River alone is home to about 120 fish species, including walleye, sauger, largemouth bass, smallmouth bass, white bass, northern pike, bluegill, crappie, channel catfish, flathead catfish, common shiner, freshwater drum, and shovelnose sturgeon.


Other fauna

A large number of reptiles are native to the river channels and basin, including American alligators, several species of turtle, aquatic amphibians, and cambaridae crayfish, are native to the Mississippi basin. In addition, approximately 40% of the Bird migration, migratory birds in the US use the Mississippi River corridor during Spring and Fall migrations; 60% of all migratory birds in
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
(326 species) use the river basin as their flyway.


Introduced species

Numerous introduced species are found in the Mississippi and some of these are Invasive species, invasive. Among the introductions are fish such as Asian carp, including the silver carp that have become infamous for out-competing native fish and their potentially dangerous Asian carp in North America#Jumping ability, jumping behavior. They have spread throughout much of the basin, even approaching (but not yet invading) the Great Lakes. The Minnesota Department of Natural Resources has designated much of the Mississippi River in the state as infested waters by the exotic species zebra mussels and Eurasian watermilfoil.


See also

* Atchafalaya Basin * Capes on the Mississippi River * Chemetco * Great River Road * List of crossings of the Lower Mississippi River * List of crossings of the Upper Mississippi River * List of locks and dams of the Upper Mississippi River * List of tributaries of the Mississippi River * List of longest rivers of the United States (by main stem) *
Mississippi embayment The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its conflu ...
* Mississippi River floods * Mississippi River System * ''The Waterways Journal Weekly'' * Upper Mississippi River National Wildlife and Fish Refuge


Notes


References


Further reading

* Ambrose, Stephen. ''The Mississippi and the Making of a Nation: From the Louisiana Purchase to Today'' (National Geographical Society, 2002) heavily illustrated * * Anfinson, John Ogden. ''Commerce and conservation on the Upper Mississippi River'' (US Army Corps of Engineers, St. Paul District, 1994) * * Botkin, Benjamin Albert. ''A Treasury of Mississippi River folklore: stories, ballads & traditions of the mid-American river country'' (1984). * Carlander, Harriet Bell. ''A history of fish and fishing in the upper Mississippi River'' (PhD Diss. Iowa State College, 1954
online
(PDF) * Daniel, Pete. ''Deep'n as it come: The 1927 Mississippi River flood'' (University of Arkansas Press, 1977) * Fremling, Calvin R. ''Immortal river: the Upper Mississippi in ancient and modern times'' (U. of Wisconsin Press, 2005), popular history * Milner, George R. "The late prehistoric Cahokia cultural system of the Mississippi River valley: Foundations, florescence, and fragmentation." ''Journal of World Prehistory'' (1990) 4#1 pp: 1–43. * Morris, Christopher. ''The Big Muddy: An Environmental History of the Mississippi and Its Peoples From Hernando de Soto to Hurricane Katrina'' (Oxford University Press; 2012) 300 pages; links drought, disease, and flooding to the impact of centuries of increasingly intense human manipulation of the river. * * * *


External links


Mississippi River
project of the American Land Conservancy
Flood management in the Mississippi River

Friends of the Mississippi River
*
Mississippi River Challengeannual canoe & kayak event on the Twin Cities stretch
*
Mississippi River Field Guide
{{Authority control Mississippi River, Mississippi River watershed, . American Heritage Rivers Borders of Arkansas Borders of Illinois Borders of Iowa Borders of Kentucky Borders of Louisiana Borders of Minnesota Borders of Mississippi Borders of Missouri Borders of Tennessee Borders of Wisconsin Rivers of Arkansas Rivers of Illinois Rivers of Iowa Rivers of Kentucky Rivers of Louisiana Rivers of Minnesota Rivers of Mississippi Rivers of Missouri Rivers of Tennessee Rivers of Wisconsin Mississippi embayment