Mississippi River & large river systems

[IowaBasser]

May 20th I'm fishing a small tournament on the Mississippi River near Prairie Du Chien, Wisconsin. The problem is I have little to no experience fishing on a large river system. Then why a tournament on the Mississippi you ask? ...My fishing buddy has a nice boat and fishes the Mississippi 3 or 4 times a summer and I've finally talked him into trying a tournament. He wanted to fish where he had some experience.

There are nearly endless back-water sloughes to fish. I've checked out some of the local bass tournaments from May 2011, and most of them were won fishing grass and weeds in very shallow water (less than 3 feet.) That was last year and the Mississippi was near flood stage most of the spring. This year we've had a mild, relatively dry winter and the water levels are down on the Mississippi.

I expect water levels will have a huge impact on fishing conditions. I will be relying heavily on my buddy's knowledge of the river; however I was hoping to pick-up some pointers on what to look for in large river systems.