A deep hole produced in the Ohio River by suction dredging was measured over a period of two years before and after high water periods. The hole did not fill, but scoured slightly deeper after each high water and the walls remained almost vertical. A vortex or circular eddy developed in the surface flow during high water and sediment was removed from the hole and deposited between the hole and the bank. The movement of water and sediment in a model hole in a flume indicated that a vortex mechanism involving a balance of scour and fill is keeping the hole free of sediment during each period of flood. The sequence of sedimentary structures for the model hole included foreset type beds and dune bedding migrating both upstream and downstream. The final structures preserved depend on the relative lengths of the phases of scour and fill and the maximum mean velocity of the stream.