Mississippi River System

The Mississippi River System is a big network of rivers in the United States. It includes the Mississippi River and many smaller rivers that flow into it. This system is the largest drainage area in the United States, covering about 41% of the country's land.

The main rivers in this system are the Arkansas, Illinois, Missouri, Ohio, and Red rivers. Before reaching the Gulf of Mexico, the Mississippi River joins its distributary, the Atchafalaya River. These rivers work together to move water across the land.

Today, this river system is also used for moving goods. It connects to other important waterways like the Illinois Waterway, the Tennessee-Tombigbee Waterway, and the Gulf Intracoastal Waterway. The U.S. Army Corps of Engineers keeps these waterways deep enough for large boats called barges to travel.

The Mississippi River helps carry many important things, such as 60% of U.S. grain shipments, 22% of oil and gas shipments, and 20% of coal. This makes the river very important for moving goods across the country.

Major tributaries

Further information: List of tributaries of the Mississippi River

Upper Mississippi River

The Upper Mississippi River is about 1,250 miles long, starting from Lake Itasca in Minnesota and ending at Cairo, Illinois. Much of this part of the river runs through an area called the Driftless Area, which didn’t get covered by glaciers. This area has many limestone cliffs shaped by water from melting glaciers. The riverbed is made of layers of clay, silt, loam, and sand, sitting on top of older glacial material.

This part of the Mississippi River makes up about half of the whole river. Around 850 miles of it can be used for boats, from near Minneapolis-St. Paul to where it meets the Ohio River. The river is home to many kinds of fish and freshwater mussels.

Arkansas River

The Arkansas River is a big tributary of the Mississippi River. It flows from Colorado to the Mississippi, passing through Kansas, Oklahoma, and Arkansas. At 1,469 miles long, it is the sixth-longest river in the United States and the second-longest tributary of the Mississippi River System.

Illinois River

The Illinois River is an important tributary of the Mississippi River, stretching about 273 miles through Illinois. It was a key water route for Native Americans and early French traders, linking the Great Lakes to the Mississippi. The river meets the Mississippi near Grafton.

It is fairly shallow and managed similarly to the Mississippi. In 1848, a canal opened connecting Lake Michigan to the Mississippi through the Illinois River, helping trade grow.

Missouri River

The Missouri River is very long, starting in southwest Montana and flowing 2,522 miles through six states before joining the Mississippi at St. Louis. It is the longest river in North America and was a major route for explorers and settlers moving west in the 1800s.

Ohio River

The Ohio River is 981 miles long, beginning where the Allegheny and Monongahela Rivers meet in Pittsburgh, Pennsylvania, and ending at Cairo, Illinois, where it flows into the Mississippi. The river passes through parts of eight states.

It can provide water for over five million people. At its widest point near Smithland dam, it is one mile across. The depth changes because of dams, averaging about 27 feet near Cincinnati but reaching up to 168 feet near Louisville, Kentucky. This depth supports many fish species and allows boats to carry cargo. Most of the cargo is energy resources like coal, and the river also helps produce energy with dams and power plants.

Red River of the South

The Red River of the South is the 10th longest river in the United States, stretching 1,290 miles. It starts near the Rocky Mountains and flows through Texas, Oklahoma, Arkansas, and Louisiana before joining the Mississippi. The river passes mostly through farmland, with major nearby cities being Shreveport, Louisiana and Alexandria, Louisiana. The Red River has many oil fields and is salty due to ancient seas that once covered the area.

Major distributaries

Mississippi River Delta

The Mississippi River Delta formed over thousands of years from sand, clay, and other materials carried by the Mississippi River into the Gulf of Mexico. It is a rich home for many animals and plants and has helped the United States grow economically.

However, over the past few hundred years, the delta has been shrinking because humans have changed the river system. As the land disappears, it becomes harder to protect what remains. The delta is very important for the animals, people, and the economy. If the land keeps disappearing at the current rate, these benefits could be lost.

Atchafalaya River

The Atchafalaya River is one of the main rivers that branches off from the Mississippi River System. It flows for 170 miles (270 km) and is one of the longest such rivers. Its name means "long river" in the language of the Native American people. The river helps businesses by providing a shorter route to the Gulf of Mexico, saving time and money.

The Old River Control Structure directs some of the water from the Mississippi River into the Atchafalaya River. This control ensures that 30% of the water from the Mississippi and Red Rivers flows into the Atchafalaya River, while the rest continues down the Mississippi River.

Historical use

Further information: Mississippi River § History

The Mississippi River System has been very important to the people who lived near it. Many Native American groups, such as the Ojibwa, Ho-Chunk, Meskwaki, and Choctaw Native Americans, settled close to the river because it provided food, helped with farming, and was a place for trading.

Later, a group known as the Mound Builders built big farming communities along the rivers. The soil from the river made the land very good for growing crops. During the U.S. Civil War, the river was also used for moving troops and had many important battles. The writer Mark Twain wrote famous stories about life on the rivers, which helped shape American literature.

Modern use

The Mississippi River System and its connected rivers are mainly used today to move goods like iron, steel, and mining products across the country. Each year, more than 460 million short tons (420 million metric tons) of items travel on the Mississippi River. The most common way to move these goods is by tugboats pushing large barges along the rivers.

Commerce

The Mississippi River System is very important for the U.S. economy. It helps send out 92% of the nation’s farm exports and 78% of the world’s feed grains and soybeans. It also has some of the biggest ports in the U.S., like the Port of South Louisiana and the Port of New Orleans.

These two ports move over 500 million tons of goods each year, more than most other U.S. ports. Common items shipped include petroleum, iron, steel, grain, rubber, paper, wood, coffee, coal, chemicals, and edible oils.

Goods movement

The commodities moved on the Mississippi River in 1999 included the following:

Ecology

Further information: Mississippi River § Ecology

Natural history

The Mississippi River System began shaping about two billion years ago. Environmental changes created mountain systems, and erosion formed depressions in the land. Over time, water from nearby oceans flooded the area, and glaciers up to 1.2 miles thick changed the landscape. When glaciers melted about 15,000 years ago, they left behind large amounts of water that helped form the rivers we see today.

The Mississippi River starts at Lake Itasca in northern Minnesota as a small stream and flows 2,350 miles south to the Gulf of Mexico. It is now connected to many smaller rivers, called tributaries, which together make up the Mississippi River System.

Wildlife

The Mississippi River and its surrounding areas are home to many different plants and animals. There are at least 260 kinds of fish in the river. Many birds, including forty percent of the United States' migratory waterfowl, use the river when they travel north and south each year. The river is also an important path for 326 types of birds in North America. There are 38 kinds of mussels found in parts of the river, and some areas may have up to 60 different kinds. The area also supports more than 50 kinds of mammals, as well as many amphibians and reptiles.

Human impacts

People have greatly affected the Mississippi River System, mainly through pollution. Even with rules to stop pollution, harmful chemicals from fertilizers and insecticides still get into the water and change the natural balance of plants and animals.

Today, the Mississippi River looks very different from its natural state because of human activity. Faster runoff and more soil moving into the water have caused problems, especially in areas where there is a lot of farming.

Flooding

In 1993, a huge flood covered seventeen thousand square miles of land across nine states. It was called a “hundred year flood” because it is very rare — something that might happen only once in a hundred years. The flooding caused a lot of damage to homes and cost a lot of money. Many people had to leave their homes because of the damage.

To help prevent future floods, the Army Corps of Engineers works to keep the rivers well-maintained. They have built levees — long walls — to control the river’s flow and floodways to redirect extra water away from populated areas. While these help stop flooding, they can sometimes make it harder for farms to grow crops.