section_path: Length
section_name: Length
paragraph_text: Length
  
  When measured from its traditional source at Lake Itasca, the Mississippi has a length of 2,340 miles (3,766 km). When measured from its longest stream source (most distant source from the sea), Brower's Spring in Montana, the source of the Missouri River, it has a length of 3,710 miles (5,971 km), making it the fourth longest river in the world after the Nile, Amazon, and Yangtze. When measured by the largest stream source (by water volume), the Ohio River, by extension the Allegheny River, would be the source, and the Mississippi would begin in Pennsylvania.