How many states does the Mississippi River and its tributaries drain?
Along with its major tributary, the Missouri River, the river drains all or parts of 31 U.S. states stretching from the Rocky Mountains in the west to the Appalachian Mountains in the east to the Canada-U.S. border on the north, including most of the Great Plains, and is the fourth longest river in the world and the tenth most powerful river in the world.
