The Mississippi River is traditionally measured as 2,340 miles (3,766 km) long from its source at Lake Itasca in Minnesota to its mouth at the Gulf of Mexico
. However, when combined with its longest tributary, the Missouri River, the entire Mississippi-Missouri river system extends about 3,710 miles (5,971 km), making it the fourth longest river system in the world after the Nile, Amazon, and Yangtze Rivers
. In summary:
- Length of Mississippi River proper (Lake Itasca to Gulf): approximately 2,340 miles (3,766 km)
- Length including Missouri River source: approximately 3,710 miles (5,971 km)
The exact length can vary due to changes in the river channel and measurement methods, but 2,340 miles is the commonly accepted length for the Mississippi River itself
