The Mississippi River is the second longest river in the United States, with a length of 2,320 mi (3,734 km) from its source in Lake Itasca in Minnesota to its mouth in Gulf of Mexico. The longest is its tributary the Missouri River measuring 2,341 mi (3,767 km).
The Mississippi River is part of the Jefferson-Missouri-Mississippi river system, which is the largest river system in North America and among the largest in the world: by length (3,900 mi or 6,275 km), it is the fourth longest, and by average discharge of 572,000 cu ft/s (16,200 m³/s), it is the tenth largest.
The longest of the many long Mississippi tributaries is the Missouri River with the Arkansas River as second longest. Measured by water volume, the largest of all Mississippi tributaries is the Ohio River.
The name Mississippi is derived from the Ojibwe word misi-ziibi ("Great River") or gichi-ziibi ("Big River") at its headwaters.
