beartrap

am planning trip down river in small boat(16ft Xpress/25 h.p. Yamaha) from yankton,S.D. to St. louis probably in july....currently in process of gathering info about the river and one thing that is important for me to know is at what river stage is the water high enough to enable you to run over the rock dikes as opposed to having to stay strictly in the channel...as a for instance...when traveling on miss. River,if river stage at St. Louis is 20 ft. or higher there is gonna be several feet of water on top of the dikes all the way to Cairo,Ill. appreciate any help or advice on this or any aspect of traveling the Missouri........ thanks dave krantz albany,ga.