Can't say I've fished your area before but here is some info that may or may not help.
Not sure if any of these fly fishing clubs are close by but you would know the area better than I.
If you like to use dry flies tie on a dropper of a beadhead nymph and you should increase your odds at a take. Use beadhead nymphs such as pheasant tail or hairs ear nymphs. Try also wooly buggers, clousers or a decievers pattern as well. You may need using lead shot to weight your line down in order to get deep. If none of this gets you to the depth you are looking for I would suggest that you look into investing a sink tip system or sinktip line, such as, the ones Cortland or Orvis provides. Of course, once you start using some sort of weighted lines casting can become more cumbersome.
If your having luck with a mosquito pattens, you might try tying on a dropper of a zebra midge or disco midge.
I hope this helps.