Who first traced the route of the Mississippi River?

Question

Who first traced the route of the Mississippi River?

Answer 1

The Native Americans  

Answer 2

René Robert Cavelier, Sieur de La Salle, or Robert de LaSalle. He was a French explorer. He explored the Great Lakes region of the United States and Canada, the Mississippi River, and the Gulf of Mexico. La Salle claimed the entire Mississippi basin for France.