I'm guessing that you were jigging off bottom in the rocks? Here at lock 12 where I fish for a couple of weeks now i can get to the river fishing at about 3:30 and by dark I will usually have a limit of crappie and a few sauger. Depending on how cold it is, I will usually stay a little after dark and squeeze out a limit of sauger too. How deep were you catching them and what color?