Mississippi River

The Mississippi River basin.

This is a list of bridges over the Mississippi in the United States. The Mississippi River is a 3,770 kilometer long river in the United States. The Missouri River is a tributary of the Mississippi, but is longer than the Mississippi in total. The Mississippi River drains much of the interior of the United States, between the Appalachian Mountains to the east and the Rocky Mountains to the west. The Mississippi has many long tributaries. Major cities on the river include Minneapolis, St. Louis, Memphis, and New Orleans. The Mississippi River is the most famous river in North America. The river basin covers 32 states and two Canadian provinces. The Mississippi River is considered the national river of the United States, and an important division between the east and west of the continent.

Upper Mississippi

The Wabasha Street Bridge in St. Paul.

The source of the Mississippi River is in Lake Ithasca in the state of Minnesota. Of all the major rivers in the United States, the Mississippi River has its lowest source, just 450 meters above sea level. The river initially flows north, later east. The first place of significance on the river is Bemidji. The river meanders strongly and flows through an area with many lakes. The area is fairly flat and mainly wooded with some agriculture here and there. From Brainerd the river is more than 100 meters wide. The river then flows south, turning the forests into prairies. Here are small towns like Little Falls and St. Cloud on the river. The river then veers southeast and then reaches the urbanized region around Minneapolis-St. Paul.

Downtown Minneapolis is located on the Mississippi River, shortly thereafter the Minnesota River flows into the Mississippi. The river here is 200 meters wide and navigable. After that, the center of the city of St. Paul is located on the Mississippi. The river then flows southeast through a series of reservoirs, forming the boundary between Minnesota and Wisconsin. At the beginning of the Boundary River at Prescott, the St. Croix River flows into it.

The Mississippi River then forms a fairly large valley as it flows south. This part mainly contains smaller towns on the river, such as Winona and LaCrosse. South of LaCrosse, the Mississippi River forms the boundary between Iowa and Wisconsin. There are no larger towns on this part, only Prairie Du Chien still has some significance, where the Wisconsin River flows into the Mississippi. Farther south is the regional city of Dubuque on the river, from this point the Mississippi forms the border between Iowa and Illinois. This section of the river runs through a hilly area, although it flattens south of Savanna, Illinois.

The river then bends slightly to the southwest, where the town of Clinton is located on the river. Larger are the Quad Cities, a collection of four cities, Davenport and Bettendorf in Iowa and Moline and Rock Island in Illinois. The river is 700 meters wide on this part. At Rock Island, the Rock River flows from Illinois into the Mississippi. From Muscatine, Iowa, the Mississippi bends south again. The Mississippi River here has increasingly larger river islands and is navigable through frequent weirs. In southern Iowa are three smaller towns on the Mississippi, Burlington, Fort Madison, and Keokuk. At Keokuk, the Des Moines River flows into the Mississippi.

The Mississippi then forms the boundary between Missouri and Illinois. Until the St. Louis region, there aren’t many significant towns on the river, only Quincy and Hannibal have some significance. The flat flow valley of the Mississippi River is up to 10 kilometers wide here. The Illinois River flows into it at Grafton. After this one reaches the metropolitan region of St. Louis. On its north side, the mighty Missouri River flows into the Mississippi, which is longer but has less drainage.

Middle Mississippi

The Eads Bridge in St. Louis.

The Middle Mississippi begins where the Missouri River flows into it. After this is the city of St. Louis at the river. On this part, the river is 600 meters wide and the banks are industrialized. The center of gravity of the urban area of St. Louis is west of the Mississippi, with mainly smaller suburbs on the Illinois side. South of St. Louis, the stream valley becomes 6 to 7 kilometers wide, especially the Missouri side has more hills and forests. There are several mining areas on the shores of Missouri. South of St. Louis, however, there are no larger towns on the Middle Mississippi River, only Sainte Genevieve and Cape Girardeau have any significance. Near Cairo, Illinois, the first large meanders in the Mississippi follow, this is at the southern tip of the state of Illinois. Near Cairo, the Ohio River flows into the Mississippi and at this point is a larger river in discharge.

Lower Mississippi

The John James Audubon Bridge over the Mississippi River in Louisiana. This is one of the most unknown large cable-stayed bridges in the United States because it is not on a major route.

The Lower Mississippi is formed from the confluence with the Ohio River. The river is already less than 100 meters above sea level at this point, despite being still deep inland. This part of the Mississippi flows more slowly and has wide floodplains. The river largely forms the boundary between Missouri and Kentucky here, although Kentucky also has land west of the river. Near New Madrid, the Mississippi has a large meander with a special border situation, in which a piece of Kentucky in the meander is separated from the rest of the state. From this point, the river forms the border between Missouri and Tennessee. The last place on the river in the state of Missouri is Caruthersville.

Farther south, the river forms the border between Arkansas and Tennessee. This part of the Mississippi has large meanders, with both states having land on the other side. One then reaches the larger city of Memphis. At Memphis, the river is usually 1 kilometer wide. South of Memphis, the river forms the border between Arkansas and Mississippi. This part of the Mississippi is rural in character, with a lot of farming and no larger towns on the river. The Mississippi here continues to have a meandering character in an otherwise fairly flat area. The Arkansas River flows into the Mississippi here. The only place of significance on this frontier stretch is Greenville, Mississippi.

The Mississippi River then forms the boundary between Louisiana and Mississippi. This is the last border stretch. The meandering river separates the Mississippi forest from the agricultural land west of it in Louisiana. The principal city on this stretch of the river is Vicksburg, a little further south is Natchez, the last significant riverside town in the state of Mississippi, after which the river flows only through Louisiana.

Through Louisiana, the river is 800 to 1000 meters wide. In this area the Atchafalaya River branches off as the western branch of the Mississippi, in which the Red River and the Ouachita River also flow. After that, the river reaches the city of Baton Rouge. From here, the banks of the Mississippi have become highly industrialized, with large petrochemical complexes on both banks. As far as New Orleans the river is very meandering and flows fairly close to Lake Pontchartrain.

From New Orleans, the heart of the Mississippi Delta begins in the Gulf of Mexico. The area mainly consists of swamps, but the river is still quite far embanked. The last place on the river is Venice. The river then splits into several branches and flows into the Gulf of Mexico.


tributary length
Minnesota River 534 km
St Croix River 272 km
Wisconsin River 680 km
Rock River 481 km
Iowa River 520 km
Des Moines River 845 km
Illinois River 439 km
Missouri River 3,767 km
Ohio River 1,579 km
Arkansas River 2,364 km

Ohio River

The Ohio River is a 1,579 kilometer long tributary of the Mississippi River, at its confluence at Cairo, Illinois, the Ohio River is greater in flow than the Mississippi River. This is because the Ohio River drains a more precipitation-rich area than the Mississippi and Missouri Rivers. The Ohio River forms in Pittsburgh, Pennsylvania and then forms the border between Ohio, Indiana and Illinois to the north and West Virginia and Kentucky to the south. The Ohio River has great significance for shipping, passing through an industrialized region.

Major cities such as Pittsburgh, Cincinnati and Louisville are located on the Ohio River. The Ohio River has many other major tributaries, such as the Tennessee River, Cumberland River, Wabash River, Allegheny River, Monongahela River, and Kanawha River, which drain the western half of the Appalachians and the eastern part of the Midwest.

Missouri River

The Missouri River is longer than the entire Mississippi River and rises in the Rocky Mountains in Montana. The Missouri River is 3,767 kilometers long. The flow is comparable at the confluence with the Mississippi River. The river drains much of the central north of the United States and also has many east-west oriented tributaries. The Missouri River flows through Montana, North Dakota, South Dakota, Nebraska, Iowa, Kansas, and Missouri. The river flows into the Mississippi River at St. Louis. Major cities on the Missouri River include Omaha and Kansas City. The watershed also includes the extreme south of the Canadian provinces of Alberta and Saskatchewan.

Arkansas River

The Arkansas River is a 2,364-mile river, and the sixth longest river in the United States. The river rises in the Rocky Mountains in Colorado and flows through the Great Plains of Kansas and then through Oklahoma and Arkansas. The Arkansas River is relatively long but has a significantly lower flow rate than the Ohio River and Missouri River, averaging 1,130 m³/s at Little Rock.


In the 1930s, a series of 29 weirs with locks were built in the Upper Mississippi between Minneapolis and St. Louis. Due to the relatively small decline of the river, the weirs are not very high. The main purpose of these weirs is to keep the Upper Mississippi navigable with a draft of at least 2.7 meters. The southernmost dam on the Mississippi River is the Chain of Rocks Dam in St. Louis. South of this, the Mississippi River has a free-flowing character, although there are many wing dams that concentrate the drainage in the middle. The dams are not designed to generate hydropower, they are also allowed to overflow if the water discharge is too great, they play no role in water regulation except for the draft.


The average flow rate at Baton Rouge is 16,800 m³/s. This makes it the twelfth largest river in the world. Near Cairo, Illinois, the Ohio River flows into the Mississippi, at this point the Ohio River has a greater discharge (8,000 m³/s) than the Mississippi River (5,900 m³/s). At the height of St. Louis, the flow rate is 4,800 m³/s.

The Mississippi River and its tributaries drain much of the interior of the United States, nearly all of the land between the Appalachian Mountains and the Rocky Mountains. In general, precipitation in the west is lower than in the east. This is also the reason that the Ohio River drains more water than the Mississippi at its confluence.

The Mississippi River valley is prone to major flooding. This has several causes, such as snowmelt in the north and subtropical depressions and ex-hurricanes in the basin. The highest discharge ever measured is 86,800 m³/s in Baton Rouge. The large-scale flooding of lowlands mainly occurs along the Mississippi River south of St. Louis and especially south of Memphis, where the height differences are smaller. These elevation changes also mean that flooding along the Upper Mississippi and along the Ohio River has less of an impact. Larger floods along the Missouri River also occur periodically, especially in the spring when a lot of snow melts at once.

The most critical point of flooding is the city of New Orleans. Especially a combination of high water discharge and backwater from the Gulf of Mexico makes this city vulnerable. To protect New Orleans from flooding, the Bonnet Carré Spillway was inaugurated in 1931, an artificial outlet from the Mississippi River to Lake Pontchartrain, just west of New Orleans.

Further north in Louisiana, the Old River Control Structure was constructed in 1963 to prevent the main flow of the Mississippi River from moving to the Atchafalaya River. Slightly further south is the Morganza Spillway, another emergency outlet where river water can flow into the Atchafalaya River at high tide, without the risk of the Mississippi River diverting its bed to the Atchafalaya River.

The Mississippi as a waterway

The Stan Musical Bridge in St. Louis.

The Mississippi River and Ohio River are critical waterways in the interior of the United States. This importance was already apparent at the beginning of the 19th century, with intensive shipping with steamers. This was in the period when there were no roads or railways and water transport was the only option.

On the Mississippi River and Ohio River there are large barges, often large convoys, some ships push dozens of barges. The river is free-flowing south of St. Louis, so ships don’t need locks. Thanks to 29 locks, the Mississippi River is navigable for fairly large ships as far as Minneapolis. The Ohio River is navigable for large ships along its entire length and has numerous locks.

South of Baton Rouge, the Mississippi River is navigable for large ocean-going vessels with a draft of up to 14 meters. This will allow large container ships, oil tankers and bulk carriers to moor along the many industrial complexes along the river between Baton Rouge and New Orleans. These facilities are collectively called the Port of South Louisiana and it is the largest port in the United States by tonnage, mainly due to the large volumes of bulk products. 60 percent of the grain from the Midwest is exported through the Port of South Louisiana. The Port of New Orleans is seen separately from this and is also one of the larger ports in the country.

The largest inland port is at St. Louis, where the shores are highly industrialized in both Missouri and Illinois. Smaller towns such as Davenport or Dubuque also have extensive water-related industries. In addition to the ports in the larger cities, there are also numerous individual industrial sites along the river that make use of supply and disposal by ship.

The Missouri River was designed for shipping as far as Sioux City, but most of it takes place between Kansas City and St. Louis. However, the volume of shipping on the Missouri River is well below its potential. In Kansas City there is a lot of industry along the river, but few of them have water-related facilities.


The original I-74 Bridge in Davenport, now replaced.

The first bridges were mostly railroad bridges, especially at Memphis and St. Louis. The oldest road bridge still in use is the Eads Bridge in St. Louis from 1874. Most bridges were built over the Mississippi in the period 1925-1975, almost all as steel cantilever truss bridges. A few arch bridges were also built in the 1970s, but this type is relatively rare. Since the 1980s, existing bridges have been replaced by new bridges, often wider, and often also because of the poor condition of the old bridges. Often, but not always, these are cable-stayed bridges.

In 2007, the I-35W Mississippi River Bridge in Minneapolis collapsed. This bridge type was found to have a design flaw and the state of Minnesota replaced almost all bridges over the Mississippi River in the years since. A total of 9 bridges south of Minneapolis were replaced in the period 2004-2018.

Mississippi River