No Single River Flows Through Both Wisconsin and Louisiana

There is no river that passes through or by both Wisconsin and Louisiana. The states are separated by ~1,000 miles and distinct drainage basins:

• Wisconsin (Upper Midwest): Drained by the Mississippi River (western border), Wisconsin River, Fox River, Wolf River, and Lake Michigan tributaries—all flowing to the Mississippi or Great Lakes.
• Louisiana (Deep South): Drained by the Mississippi River (main stem), Red River, Ouachita River, Atchafalaya River, and coastal bayous—all flowing to the Gulf of Mexico.

The Mississippi River connects them hydrologically—it flows along Wisconsin's western border and through Louisiana—but no single river originates in or uniquely passes both states. The Mississippi is the continental-scale collector linking the Upper Midwest to the Gulf.