Misplaced Pages

Upper Mississippi River

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
#284715

79-685: 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 . Historically, it may refer to the area above the Arkansas Post , above the confluence of Ohio River , or above Cape Girardeau . In terms of geologic and hydrographic history, the Upper Mississippi east and south of Fort Snelling

158-420: A depth of 2.75 meters (9 ft). The agriculture and barge transportation industries have lobbied in the late 20th and early 21st centuries for a multibillion-dollar project to upgrade the aging lock and dam system. Some environmental groups and advocates of budgetary restraint argue that the project lacks economic justification. Each lock and dam complex creates a pool upstream of it. There are 29 locks on

237-542: A large mound of sand spanning the width of the river 55 feet below the surface, allowing fresh water and large cargo ships to pass over. Fresh river water flowing from the Mississippi into the Gulf of Mexico does not mix into the salt water immediately. The images from NASA 's MODIS show a large plume of fresh water, which appears as a dark ribbon against the lighter-blue surrounding waters. These images demonstrate that

316-734: A length of 3,710 miles (5,971 km), making it the fourth longest river in the world after the Nile , Amazon , and Yangtze . When measured by the largest stream source (by water volume), the Ohio River , by extension the Allegheny River , would be the source, and the Mississippi would begin in Pennsylvania . At its source at Lake Itasca , the Mississippi River is about 3 feet (0.91 m) deep. The average depth of

395-478: A natural process known as avulsion or delta switching, the lower Mississippi River has shifted its final course to the mouth of the Gulf of Mexico every thousand years or so. This occurs because the deposits of silt and sediment begin to clog its channel, raising the river's level and causing it to eventually find a steeper, more direct route to the Gulf of Mexico. The abandoned distributaries diminish in volume and form what are known as bayous . This process has, over

474-638: A total of 465 square kilometers (285,000 ac). The largest of them, the Upper Mississippi River National Wildlife and Fish Refuge , is over 420 kilometers (260 mi) long, reaching from the Alma , Wisconsin area down to Rock Island , Illinois . The refuge consists of blufflands, marshes, bottomland forest, islands, channels, backwater lakes and sloughs. It is part of the Mississippi Flyway . Although

553-794: Is 208,200 cu ft/s (5,900 m /s). Thus, by volume, the main branch of the Mississippi River system at Cairo can be considered to be the Ohio River (and the Allegheny River further upstream), rather than the Middle Mississippi. In addition to the Ohio River , the major tributaries of the Lower Mississippi River are the White River , flowing in at the White River National Wildlife Refuge in east-central Arkansas;

632-512: Is a meandering river in a broad, flat area, only rarely flowing alongside a bluff (as at Vicksburg, Mississippi ). The Mississippi River is known as the Middle Mississippi from the Upper Mississippi River's confluence with the Missouri River at St. Louis, Missouri , for 190 miles (310 km) to its confluence with the Ohio River at Cairo, Illinois . The Middle Mississippi is relatively free-flowing. From St. Louis to

711-661: Is a portion of the now-extinct Glacial River Warren which carved the valley of the Minnesota River , permitting the immense Glacial Lake Agassiz to join the world's oceans at the Gulf of Mexico . The collapse of ice dams holding back Glacial Lake Duluth and Glacial Lake Grantsburg carved out the Dalles of the St. Croix River at Interstate Park . The Upper Mississippi River valley likely originated as an ice-marginal stream during

790-498: Is called the Lower Mississippi River from its confluence with the Ohio River to its mouth at the Gulf of Mexico, a distance of about 1,000 miles (1,600 km). At the confluence of the Ohio and the Middle Mississippi, the long-term mean discharge of the Ohio at Cairo, Illinois is 281,500 cubic feet per second (7,970 cubic meters per second), while the long-term mean discharge of the Mississippi at Thebes, Illinois (just upriver from Cairo)

869-801: Is controlled and managed as a series of pools created by 26 locks and dams. The Upper Mississippi River is joined by the Minnesota River at Fort Snelling in the Twin Cities ; the St. Croix River near Prescott, Wisconsin ; the Cannon River near Red Wing, Minnesota ; the Zumbro River at Wabasha, Minnesota ; the Black , La Crosse , and Root rivers in La Crosse, Wisconsin ; the Wisconsin River at Prairie du Chien, Wisconsin ;

SECTION 10

#1732765613285

948-520: Is largely a multi-thread stream with many bars and islands. From its confluence with the St. Croix River downstream to Dubuque, Iowa , the river is entrenched, with high bedrock bluffs lying on either side. The height of these bluffs decreases to the south of Dubuque, though they are still significant through Savanna, Illinois . This topography contrasts strongly with the Lower Mississippi, which

1027-414: Is part of Pool 4 of the Upper Mississippi River. National and regional efforts are addressing these problems, but nutrient impairment problems are occurring elsewhere in the Upper Mississippi River as well, particularly in off-channel portions. Excessive nutrients contribute to thick floating mats of filamentous algae or duckweeds that have a pronounced negative impact on light penetration and may threaten

1106-667: Is the National Park Service site dedicated to protecting and interpreting the Mississippi River itself. The other two National Park Service sites along the river are: Effigy Mounds National Monument and the Gateway Arch National Park (home to the Gateway Arch in St. Louis ). Unlike the Lower Mississippi, much of the upper river is a series of pools created by a system of 29 locks and dams . The structures were authorized by Congress in

1185-539: Is the only true waterfall on the entire Mississippi River. The water elevation continues to drop steeply as it passes through the gorge carved by the waterfall. After the completion of the St. Anthony Falls Lock and Dam in 1963, the river's head of navigation moved upstream, to the Coon Rapids Dam . However, the Locks were closed in 2015 to control the spread of invasive Asian carp , making Minneapolis once again

1264-618: The American Civil War , the Mississippi's capture by Union forces marked a turning point towards victory , due to the river's strategic importance to the Confederate war effort. Because of the substantial growth of cities and the larger ships and barges that replaced steamboats, the first decades of the 20th century saw the construction of massive engineering works such as levees , locks and dams , often built in combination. A major focus of this work has been to prevent

1343-880: The Arkansas River , joining the Mississippi at Arkansas Post ; the Big Black River in Mississippi; and the Yazoo River , meeting the Mississippi at Vicksburg, Mississippi . Deliberate water diversion at the Old River Control Structure in Louisiana allows the Atchafalaya River in Louisiana to be a major distributary of the Mississippi River, with 30% of the combined flow of the Mississippi and Red Rivers flowing to

1422-590: The Gulf of Mexico , part of the Atlantic Ocean. The total catchment of the Mississippi River covers nearly 40% of the landmass of the continental United States. The highest point within the watershed is also the highest point of the Rocky Mountains , Mount Elbert at 14,440 feet (4,400 m). In the United States, the Mississippi River drains the majority of the area between the crest of

1501-603: The Minnesota River , James River , and Milk River valleys. When the ice sheet completely retreated, many of these "temporary" rivers found paths to Hudson Bay or the Arctic Ocean, leaving the Mississippi Basin with many features "over-sized" for the existing rivers to have carved in the same time period. Ice sheets during the Illinoian Stage , about 300,000 to 132,000 years before present, blocked

1580-476: The Pre-Illinoian Stage . The Driftless Area is a portion of North America left unglaciated at that ice age's height, hence not smoothed out or covered over by previous geological processes. The Upper Mississippi from below St. Anthony Falls ( Minneapolis , Minnesota ) downstream to St. Paul, Minnesota is a gorge with high limestone bluffs carved by the waterfall. Upstream of the waterfall

1659-1252: The Rock River at the Quad Cities ; the Iowa River near Wapello, Iowa ; the Skunk River south of Burlington, Iowa ; and the Des Moines River at Keokuk, Iowa . Other major tributaries of the Upper Mississippi include the Crow River in Minnesota, the Chippewa River in Wisconsin, the Maquoketa River and the Wapsipinicon River in Iowa, and the Illinois River in Illinois. The Upper Mississippi

SECTION 20

#1732765613285

1738-887: The Rocky Mountains and the crest of the Appalachian Mountains , except for various regions drained to Hudson Bay by the Red River of the North ; to the Atlantic Ocean by the Great Lakes and the Saint Lawrence River ; and to the Gulf of Mexico by the Rio Grande , the Alabama and Tombigbee rivers, the Chattahoochee and Appalachicola rivers, and various smaller coastal waterways along

1817-613: The United States Census Bureau , the city has a total area of 7.9 square miles (20.46 km ), of which, 5.31 square miles (13.75 km ) are land and 2.59 square miles (6.71 km ) are covered by water. According to the Köppen Climate Classification system, Alma has a hot-summer humid continental climate , abbreviated "Dfa" on climate maps. The hottest temperature recorded in Alma

1896-429: The headwaters region and serve multiple purposes, including power generation and recreation. The remaining 29 dams, beginning in downtown Minneapolis, all contain locks and were constructed to improve commercial navigation of the upper river. Taken as a whole, these 43 dams significantly shape the geography and influence the ecology of the upper river. Beginning just below Saint Paul, Minnesota , and continuing throughout

1975-491: The most recent Ice Age . The southernmost extent of this enormous glaciation extended well into the present-day United States and Mississippi basin. When the ice sheet began to recede, hundreds of feet of rich sediment were deposited, creating the flat and fertile landscape of the Mississippi Valley. During the melt, giant glacial rivers found drainage paths into the Mississippi watershed, creating such features as

2054-564: The 1930s, and most were completed by 1940. A primary reason for damming the river is to facilitate barge transportation. The dams regulate water levels for the Upper River and play a major part in regulating levels on the Lower Mississippi. On the upper reaches near the Minnesota- Wisconsin border, the river's floodplain is between 1.5 and 5 kilometers (between 1 and 3 mi) wide. South of St. Louis , Missouri ,

2133-579: The Earth's mantle (specifically, the Bermuda hotspot ) that was undergoing a period of intense activity. The upwelling of magma from the hotspot forced the further uplift to a height of perhaps 2–3 km of part of the Appalachian-Ouachita range, forming an arch that blocked southbound water flows. The uplifted land quickly eroded and, as North America moved away from the hot spot and as

2212-632: The French rendering of the Anishinaabe ( Ojibwe or Algonquin ) name for the river, Misi-ziibi (Great River). In the 18th century, the river was set by the Treaty of Paris as, for the most part, the western border of the new United States. With the Louisiana Purchase and the country's westward expansion, it became a convenient boundary line between the western and eastern halves of

2291-656: The Gulf of Mexico by this route, rather than continuing down the Mississippi's current channel past Baton Rouge and New Orleans on a longer route to the Gulf. Although the Red River was once an additional tributary, its water now flows separately into the Gulf of Mexico through the Atchafalaya River. The Mississippi River has the world's fourth-largest drainage basin ("watershed" or "catchment"). The basin covers more than 1,245,000 square miles (3,220,000 km ), including all or parts of 32 U.S. states and two Canadian provinces. The drainage basin empties into

2370-495: The Gulf. The Mississippi River empties into the Gulf of Mexico about 100 miles (160 km) downstream from New Orleans. Measurements of the length of the Mississippi from Lake Itasca to the Gulf of Mexico vary somewhat, but the United States Geological Survey 's number is 2,340 miles (3,766 km). The retention time from Lake Itasca to the Gulf is typically about 90 days; while speed varies along

2449-469: The Illinoian Stage. Timeline of outflow course changes In March 1876, the Mississippi suddenly changed course near the settlement of Reverie, Tennessee , leaving a small part of Tipton County, Tennessee , attached to Arkansas and separated from the rest of Tennessee by the new river channel. Since this event was an avulsion , rather than the effect of incremental erosion and deposition,

Upper Mississippi River - Misplaced Pages Continue

2528-578: The Midwestern and eastern U.S. These earthquakes created Reelfoot Lake in Tennessee from the altered landscape near the river. When measured from its traditional source at Lake Itasca , the Mississippi has a length of 2,340 miles (3,766 km). When measured from its longest stream source (most distant source from the sea), Brower's Spring in Montana , the source of the Missouri River , it has

2607-480: The Mississippi River between Saint Paul and Saint Louis is between 9 and 12 feet (2.7–3.7 m) deep, the deepest part being Lake Pepin , which averages 20–32 feet (6–10 m) deep and has a maximum depth of 60 feet (18 m). Between where the Missouri River joins the Mississippi at Saint Louis, Missouri, and Cairo, Illinois, the depth averages 30 feet (9 m). Below Cairo, where the Ohio River joins,

2686-411: The Mississippi River has experienced numerous large and small changes to its main course, as well as additions, deletions, and other changes among its numerous tributaries, and the lower Mississippi River has used different pathways as its main channel to the Gulf of Mexico across the delta region. As Pangaea began to break up about 95 million years ago, North America passed over a volcanic " hotspot " in

2765-469: The Mississippi River near New Madrid, Missouri , between Memphis and St. Louis, is related to an aulacogen (failed rift) that formed at the same time as the Gulf of Mexico. This area is still quite active seismically. Four great earthquakes in 1811 and 1812 , estimated at 8 on the Richter magnitude scale , had tremendous local effects in the then sparsely settled area, and were felt in many other places in

2844-593: The Mississippi River. Alma, Wisconsin Alma ( / ˈ ɑː l m ə / AHL -mə ) is a city in and the county seat of Buffalo County, Wisconsin , United States. The population was 716 at the 2020 census . Alma was named in commemoration of the Battle of Alma , in the Crimean War. Alma is located on State Route 35 , about 6 miles (9.7 km) east of Wabasha, Minnesota . According to

2923-404: The Mississippi near Rock Island, Illinois, diverting it to its present channel farther to the west, the current western border of Illinois. The Hennepin Canal roughly follows the ancient channel of the Mississippi downstream from Rock Island to Hennepin, Illinois . South of Hennepin, to Alton, Illinois , the current Illinois River follows the ancient channel used by the Mississippi River before

3002-529: The Missouri River; the Middle Mississippi, which is downriver from the Missouri to the Ohio River; and the Lower Mississippi , which flows from the Ohio to the Gulf of Mexico. The Upper Mississippi runs from its headwaters to its confluence with the Missouri River at St. Louis, Missouri. It is divided into two sections: The source of the Upper Mississippi branch is traditionally accepted as Lake Itasca , 1,475 feet (450 m) above sea level in Itasca State Park in Clearwater County, Minnesota . The name Itasca

3081-443: The Ohio River confluence, the Middle Mississippi falls 220 feet (67 m) over 180 miles (290 km) for an average rate of 1.2 feet per mile (23 cm/km). At its confluence with the Ohio River, the Middle Mississippi is 315 feet (96 m) above sea level. Apart from the Missouri and Meramec rivers of Missouri and the Kaskaskia River of Illinois, no major tributaries enter the Middle Mississippi River. The Mississippi River

3160-422: The Upper Mississippi River are working together to address water quality issues. The Minnesota Pollution Control Agency planned to test the entire 650-mile length (1,050 km) of the river within the state for the first time in 2024. There is general agreement that nutrients are contributing to the Gulf of Mexico dead zone and to eutrophication problems in Lake Pepin , a large natural riverine lake that

3239-430: The Upper Mississippi River is the Upper St. Anthony Falls Lock and Dam in Minneapolis. Above the dam, the river's elevation is 799 feet (244 m). Below the dam, the river's elevation is 750 feet (230 m). This 49-foot (15 m) drop is the largest of all the Mississippi River locks and dams. The origin of the dramatic drop is a waterfall preserved adjacent to the lock under an apron of concrete. Saint Anthony Falls

Upper Mississippi River - Misplaced Pages Continue

3318-426: The Upper Mississippi is a simple steel culvert, through which the river (locally named "Nicolet Creek") flows north from Lake Nicolet under "Wilderness Road" to the West Arm of Lake Itasca, within Itasca State Park . The earliest bridge across the Mississippi River was built in 1855. It spanned the river in Minneapolis where the current Hennepin Avenue Bridge is located. No highway or railroad tunnels cross under

3397-410: The Upper Mississippi maintained by the U.S. Army Corps of Engineers —from Upper St. Anthony Falls upstream to Chain of Rocks downstream. The locks provide a collective 123 meters (404 ft) of lift. The Army Corps of Engineers has studied expanding locks 20 , 21 , 22 , 24 , and 25 on the Upper Mississippi. Mississippi River The Mississippi River is the primary river of

3476-420: The age of 18 living with them, 52.5% were married couples living together, 6.4% had a female householder with no husband present, and 37.8% were non-families. 31.4% of all households were made up of individuals, and 14.5% had someone living alone who was 65 years of age or older. The average household size was 2.20 and the average family size was 2.74. In the city, the population was spread out, with 19.7% under

3555-460: The age of 18, 7.6% from 18 to 24, 25.5% from 25 to 44, 23.1% from 45 to 64, and 24.0% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 98.3 males. For every 100 females age 18 and over, there were 97.9 males. The median income for a household in the city was $ 34,250, and the median income for a family was $ 45,625. Males had a median income of $ 31,806 versus $ 21,250 for females. The per capita income for

3634-410: The alluvial floodplain is approximately 80 kilometers (50 mi) wide. Major tributaries to the Upper Mississippi River include the Missouri , Illinois , Minnesota , St. Croix , Chippewa , Black , Wisconsin , and Kaskaskia Rivers. The Upper Mississippi provides habitat for more than 125 fish species and 30 species of freshwater mussels. Three national wildlife refuges along the river cover

3713-555: The areas drained by them. Denser salt water from the Gulf of Mexico forms a salt wedge along the river bottom near the mouth of the river, while fresh water flows near the surface. In drought years, with less fresh water to push it out, salt water can travel many miles upstream—64 miles (103 km) in 2022—contaminating drinking water supplies and requiring the use of desalination . The United States Army Corps of Engineers constructed "saltwater sills" or "underwater levees" to contain this in 1988, 1999, 2012, and 2022. This consists of

3792-415: The basin in increasing numbers. The river served sometimes as a barrier, forming borders for New Spain , New France , and the early United States, and throughout as a vital transportation artery and communications link. In the 19th century, during the height of the ideology of manifest destiny , the Mississippi and several tributaries, most notably its largest, the Ohio and Missouri , formed pathways for

3871-417: The city was $ 21,885. About 5.6% of families and 8.9% of the population were below the poverty line , including 5.8% of those under age 18 and 14.5% of those age 65 or over. The Great Alma Fishing Float has been an attraction to tourists, and is particularly popular during the annual walleye run. It is located next to Lock & Dam Number 4 on the Mississippi River. Mississippi River Lock and Dam No. 4 ,

3950-485: The city. The population density was 160.8 people per square mile (62.1/km ). There were 495 housing units at an average density of 84.5 per square mile (32.6/km ). The racial makeup of the city was 97.03% White , 0.21% Black or African American , 0.85% Native American , 0.32% Asian , 0.11% Pacific Islander , and 1.49% from two or more races. 0.85% of the population were Hispanic or Latino of any race. There were 421 households, out of which 23.0% had children under

4029-411: The country. This is reflected in the Gateway Arch in St. Louis, which was designed to symbolize the opening of the West, and the focus on the " Trans-Mississippi " region in the Trans-Mississippi Exposition . Regional landmarks are often classified in relation to the river, such as "the highest peak east of the Mississippi " or "the oldest city west of the Mississippi". The FCC also uses it as

SECTION 50

#1732765613285

4108-427: The course of the river, this gives an overall average of around 26 mi (42 km) per day, or 1 mi (1.6 km) per hour. The stream gradient of the entire river is 0.01%, a drop of 450 m over 3,766 km. The Mississippi River discharges at an annual average rate of between 200 and 700 thousand cubic feet per second (6,000 and 20,000 m /s). The Mississippi is the fourteenth largest river in

4187-403: The delta of the Chippewa River of Wisconsin as it enters the Upper Mississippi, is more than 2 miles (3.2 km) wide. By the time the Upper Mississippi reaches Saint Paul , Minnesota, below Lock and Dam No. 1, it has dropped more than half its original elevation and is 687 feet (209 m) above sea level. From St. Paul to St. Louis, Missouri, the river elevation falls much more slowly and

4266-532: The depth averages 50–100 feet (15–30 m) deep. The deepest part of the river is in New Orleans, where it reaches 200 feet (61 m) deep. The Mississippi River runs through or along 10 states, from Minnesota to Louisiana , and is used to define portions of these states' borders, with Wisconsin , Illinois , Kentucky , Tennessee , and Mississippi along the east side of the river, and Iowa , Missouri , and Arkansas along its west side. Substantial parts of both Minnesota and Louisiana are on either side of

4345-405: The dividing line for broadcast call-signs , which begin with W to the east and K to the west, overlapping in media markets along the river. Due to its size and importance, it has been nicknamed The Mighty Mississippi River or simply The Mighty Mississippi . The Mississippi River can be divided into three sections: the Upper Mississippi , the river from its headwaters to the confluence with

4424-509: The growth and persistence of submerged aquatic vegetation that is important for fish and aquatic life, including waterfowl. Efforts to control nutrients from point and non-point sources in the basin have aimed to provide additional benefits. Navigation locks allow towboats , barges, and other vessels to transit the dams. Approximately 1350 kilometers (850 mi), from the head of navigation in Mile 858, Minneapolis, Minnesota down to Cairo, has been made suitable for commercial navigation with

4503-441: The hotspot's activity declined, the crust beneath the embayment region cooled, contracted and subsided to a depth of 2.6 km, and around 80 million years ago the Reelfoot Rift formed a trough that was flooded by the Gulf of Mexico . As sea levels dropped, the Mississippi and other rivers extended their courses into the embayment , which gradually became filled with sediment with the Mississippi River at its center. Through

4582-408: The land slopes gently to rivers edge. Downstream of downtown St. Paul the river enters its wide preglacial valley. The states of Minnesota , Wisconsin and Iowa , along with the federal government, have preserved certain areas of the land along this reach of the river. There are three National Park Service sites along the Upper Mississippi River. The Mississippi National River and Recreation Area

4661-460: The largest drainage basin in the United States . From its traditional source of Lake Itasca in northern Minnesota , it flows generally south for 2,340 miles (3,766 km) to the Mississippi River Delta in the Gulf of Mexico . With its many tributaries , the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The river either borders or passes through

4740-416: The largest in North America. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Many were hunter-gatherers , but some, such as the Mound Builders , formed prolific agricultural and urban civilizations, and some practiced aquaculture . The arrival of Europeans in the 16th century changed the native way of life as first explorers, then settlers, ventured into

4819-402: The last two decades, this number was only 160 million short tons (145 million metric tons) per year. The reduction in sediment transported down the Mississippi River is the result of engineering modification of the Mississippi, Missouri, and Ohio rivers and their tributaries by dams, meander cutoffs , river-training structures, and bank revetments and soil erosion control programs in

SECTION 60

#1732765613285

4898-437: The lower 10 miles (16 km) of the Kaskaskia River, forming a new Mississippi channel and cutting off the town from the rest of the state. Later flooding destroyed most of the remaining town, including the original State House. Today, the remaining 2,300 acres (930 ha) island and community of 14 residents is known as an enclave of Illinois and is accessible only from the Missouri side. The New Madrid Seismic Zone , along

4977-415: The lower Mississippi from shifting into the channel of the Atchafalaya River and bypassing New Orleans . 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 . The word Mississippi itself comes from Misi zipi ,

5056-449: The new river channel, contiguous with the adjacent state. Also, due to a meander in the river, a small part of western Kentucky is contiguous with Tennessee but isolated from the rest of its state. Many of the communities along the Mississippi River are listed below; most have either historic significance or cultural lore connecting them to the river. They are sequenced from the source of the river to its end. The road crossing highest on

5135-425: The past 5,000 years, caused the coastline of south Louisiana to advance toward the Gulf from 15 to 50 miles (24 to 80 km). The currently active delta lobe is called the Birdfoot Delta, after its shape, or the Balize Delta , after La Balize, Louisiana , the first French settlement at the mouth of the Mississippi. The current form of the Mississippi River basin was largely shaped by the Laurentide Ice Sheet of

5214-436: The plume did not mix with the surrounding sea water immediately. Instead, it stayed intact as it flowed through the Gulf of Mexico, into the Straits of Florida , and entered the Gulf Stream . The Mississippi River water rounded the tip of Florida and traveled up the southeast coast to the latitude of Georgia before finally mixing in so thoroughly with the ocean that it could no longer be detected by MODIS. Over geologic time,

5293-521: The population was 2.9% Hispanic or Latino of any race. As of the census of 2010, there were 781 people, 386 households, and 202 families living in the city. The population density was 148.2 inhabitants per square mile (57.2/km ). There were 488 housing units at an average density of 92.6 per square mile (35.8/km ). The racial makeup of the city was 98.5% White , 0.1% African American , 0.4% Native American , 0.1% Asian , and 0.9% from two or more races. Hispanic or Latino of any race were 0.6% of

5372-437: The population. There were 386 households, of which 17.1% had children under the age of 18 living with them, 41.7% were married couples living together, 7.3% had a female householder with no husband present, 3.4% had a male householder with no wife present, and 47.7% were non-families. 41.2% of all households were made up of individuals, and 21% had someone living alone who was 65 years of age or older. The average household size

5451-479: The river is much cleaner than it was in recent decades, water quality is still a priority concern. Agricultural runoff, including sediment, excessive nutrients, (particularly nitrogen and phosphorus), and chemicals from agricultural and industrial sources continue to threaten Upper Mississippi River aquatic resources. In addition new threats continue to emerge such as personal care items including pharmaceuticals and endocrine-disrupting chemicals. The five states bordering

5530-479: The river, although the Mississippi defines part of the boundary of each of these states. In all of these cases, the middle of the riverbed at the time the borders were established was used as the line to define the borders between adjacent states. In various areas, the river has since shifted, but the state borders have not changed, still following the former bed of the Mississippi River as of their establishment, leaving several small isolated areas of one state across

5609-400: The site of the head of navigation of the river. The Upper Mississippi has a number of natural and artificial lakes, with its widest point being Lake Winnibigoshish , near Grand Rapids, Minnesota , over 11 miles (18 km) across. Lake Onalaska , created by Lock and Dam No. 7 , near La Crosse, Wisconsin , is more than 4 miles (6.4 km) wide. Lake Pepin , a natural lake formed behind

5688-532: The state line still follows the old channel. The town of Kaskaskia, Illinois once stood on a peninsula at the confluence of the Mississippi and Kaskaskia (Okaw) Rivers . Founded as a French colonial community, it later became the capital of the Illinois Territory and was the first state capital of Illinois until 1819. Beginning in 1844, successive flooding caused the Mississippi River to slowly encroach east. A major flood in 1881 caused it to overtake

5767-460: The states of Minnesota , Wisconsin , Iowa , Illinois , Missouri , Kentucky , Tennessee , Arkansas , Mississippi , and Louisiana . The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km ), of which only about one percent is in Canada. The Mississippi ranks as the world's tenth-largest river by discharge flow, and

5846-573: The upper and lower river, the Mississippi is further controlled by thousands of wing dikes that moderate the river's flow in order to maintain an open navigation channel and prevent the river from eroding its banks. The head of navigation on the Mississippi is the St. Anthony Falls Lock. Before the Coon Rapids Dam in Coon Rapids, Minnesota , was built in 1913, steamboats could occasionally go upstream as far as Saint Cloud, Minnesota , depending on river conditions. The uppermost lock and dam on

5925-469: The western expansion of the United States. The river also became the subject of American literature , particularly in the writings of Mark Twain . Formed from thick layers of the river's silt deposits, the Mississippi embayment is one of the most fertile regions of the United States; steamboats were widely used in the 19th and early 20th centuries to ship agricultural and industrial goods. During

6004-479: The world by volume. On average, the Mississippi has 8% the flow of the Amazon River , which moves nearly 7 million cubic feet per second (200,000 m /s) during wet seasons. Before 1900, the Mississippi River transported an estimated 440 million short tons (400 million metric tons) of sediment per year from the interior of the United States to coastal Louisiana and the Gulf of Mexico. During

6083-428: Was 1.95 and the average family size was 2.62. The median age in the city was 50.3 years. 15.4% of residents were under the age of 18; 5.8% were between the ages of 18 and 24; 21.3% were from 25 to 44; 30% were from 45 to 64; and 27.5% were 65 years of age or older. The gender makeup of the city was 51.0% male and 49.0% female. As of the census of 2000, there were 942 people, 421 households, and 261 families living in

6162-576: Was 101 °F (38.3 °C) on June 11, 1956, while the coldest temperature recorded was −38 °F (−38.9 °C) on January 31, 1996. As of the census of 2020 , the population was 716. The population density was 134.8 inhabitants per square mile (52.0/km ). There were 479 housing units at an average density of 90.2 per square mile (34.8/km ). The racial makeup of the city was 94.7% White , 1.5% Native American , 0.6% Black or African American , 0.3% Pacific Islander , 0.1% Asian , 1.0% from other races , and 1.8% from two or more races. Ethnically,

6241-500: 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 ( ver itas ) and the first two letters of the Latin word for head ( ca put ). However, the lake is in turn fed by a number of smaller streams. From its origin at Lake Itasca to St. Louis, Missouri , the waterway's flow is moderated by 43 dams. Fourteen of these dams are located above Minneapolis in

#284715