I heard them yesterday in Vienna, Va (Fairfax County). They were buzzing in the trees at the Seldom Scene concert.
Might be nice to give cicadas a try on the Potomac nearby some time. Like in the morning, before it gets too hot.
From the map, it looks as if the Shenandoah River might be a good bet for cicadas. Maybe use a black popper, with some orange on the bottom.
Come to think of it, some sort of cork fly might make a good trout cicada imitation, too. I think fish are attracted by the ruckus that swamped cicadas put up with their wings. Anything that might impart that sort of action in the fly would be a help.