Ralph,

Are you going to be fishing up in SNP, Mossy Creek? The Mr. Rapidan http://hipwader.com/2004/tying-mrrapidan-dry-fly , was developed by Harry Murray (stop by his shop in Edinburg on the way down I-81) for the freestoners in the Park, specifically for the Quill Gordon hatch - that'll be over by May but it should still work for Grey Fox/March Brown hatches. I'd make sure to have some CDC & Elk; those are magic in the park; lots of other attractors you could try as well, Humpies, foam-back Convertibles (my favorite), etc. Mossy is another matter; I've had good luck using terrestrials, mostly late summer/fall. It has had decent sulphur hatches in the past but I haven't fished there much in a few years so I'm not sure how good it is now. Scuds and cressbugs are always worth trying, yo-yoing a conehead bugger along the banks can work at times, too although you have to be very careful to keep the vibrations from your footsteps to a minimum. Also, the electric fence along the stream is active and will deliver a nasty shock if you're not careful. If you haven't got your permit to fish there, you can pick them up at the VDGIF office in Verona, about 10 miles south of Bridgewater.

Regards,
Scott