The Mississippi River is the second longest river in the United States. How long is it? That depends on who you ask. Most estimates are between 2,300 and 2,350 miles, but some sources have it as long as 2,552 miles. It starts at Lake Itasca in northern Minnesota and makes a question mark shape as it flows 681 miles through Minnesota—the most miles of any state the river flows through. Minnesota is one of only two states the river flows mostly “through”, the other being the last state it flows through, Louisiana. For every other state the river touches (there are eight others, for a total of ten), the river serves as a border. In order, the ten states are: Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi and Louisiana. With all of it’s tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces. It is the fourth-longest river in the world and certainly the most famous river in the United States.
To move goods up and down the Mississippi, the U.S. Army Corps of Engineers maintains a 9-foot deep shipping channel from Baton Rouge, LA to Minneapolis, MN. From Baton Rouge past New Orleans to Head of Passes, a 45 foot channel is maintained to allow ocean-going vessels access to ports between New Orleans and Baton Rouge.
The river can be divided into three sections. The first section, from Lake Itasca to Minneapolis/St. Paul, has 12 dams that must be portaged around. The second “middle” section of the Mississippi, from St. Paul to St. Louis, has 29 locks and dams. At every lock there is a chance the canoeists will have to wait, up to many hours, for the lock to be ready for them to go through. Finally the “lower” Mississippi, 1,000 miles of free-flowing, fairly “wilderness-y” river but for barges, flows all the way to the Gulf of Mexico.
(Some of this information was found at the informative Mississippi River National River and Recreation Area’s website at: Mississippi River Facts)