Jacques Marquette explored the northern portion of the Mississippi River and founded Michigan's first settlement. He explored extensively in mid-western states such as modern-day Wisconsin, Illinois and Michigan. Louis Joliet is also known for exploring the Upper Mississippi and was with Jacques Marquette when Marquette explored, so they have the same exploration route. Rene-Rober Cavelier, Sieur de LaSalle explored the Great Lakes of the United States and Canada, the Mississippi River and the Gulf of Mexico.