The major rivers in Mississippi are Mississippi River, Big Black River, Pearl River, and Yazoo River. The major lakes in Mississippi are Ross Barnett Reservoir, Arkabutla Lake, Sardis Lake, Grenada Lake.
The source of the Mississippi River that flows down to the Gulf of Mexico in Louisiana is from a lake in Northern Minnesota. The lake is located in Itasca State Park and of coarse, the lake is called Lake Itasca. You can walk across rocks where the Mississippi starts.