Autobiography of James Robert Maxwell https://babel.hathitrust.org/cgi/pt?id=nnc1.cu01501160&view=1up&seq=9

From page 16 of THE AUTOBIOGRAPHY OF JAMES ROBERT MAXWELL: "These rock shoals under this bridge were the first in going upstream. About a mile above, where Lock No.10 now stands, were other rock ledges through or over which the river in low water had to find its way by several channels. These were utilized in a fishery business by a Mr. Suggs ,with several large fish traps where the water rushed through at a very rapid rate. The traps were simply a quite inclined plane ,the width of the rushing stream, with sides perhaps one to two feet high. The bottom of the plane was composed of two-inch pine slats placed one inch apart .Fish going downstream were washed up onto these slats through which the water passed, leaving the fish of all kinds flapping about just at the point where water passed through.  

These fisheries furnished a good living to the owners. They often had more fish than they could sell in certain stages of the water and seasons of the year. There being no railroads to furnish quick transportation, and no icing facilities, there was, at times, a terrible waste of good food in the shape of decaying fish."