Planes, Trains, and .....Barges

I live in the Chicago area so I definitely know the importance of planes, cars, buses, and trains in the transportation world.  On my trip, I didn't see many planes, but I did see trains, both sides of the river, running hourly if not more often, and barges.  Lots of barges.  And they are big. Huge.  I never realized how much the Mississippi River is still used to transport materials and equipment, but it must still be a vital means of transportation.