Your 20ft boat will work fine with a big motor, but the river is rolling like a freight train. I wouldn't recommend it. It's way up. They're releasing water from the dam near maximum output. I hear the duck hunting on it is productive, and I even saw a guy doing it back a couple months when the water was low. You may have to try the lake or somewhere else near by. Perhaps some other hunters can join in with some recommendations. Sorry about your luck.