Can't go wrong with hoppers and ants this time of year. Keep in mind the wet summer stunted the hopper cycle and most of them are undersized this year. Parachute Adams should work well if you can time it right. If the topwater flies don't do it for you try searching them out with a 12-14 Wooly bugger or a dual nymph rig. Anything that imitates a mayfly nymph should work well. I prefer size 14 bh hare's ear there or squirel tail nymphs in the same size. If they are hitting the nymphs but you know there is more going on down there try a pheasant tail. Size twelves sometimes work very well. Just check out some rocks below the riffles and see what you can see. Black or brown on the buggers work well as do white if you're looking to imitate bait fish. Now is a great time to wail on the smallies that are up there working the minnows and panfish over. Try a yellow popper with a red throat near dusk for some exciting top water action.