There are excellent hatches of March Browns and Light Cahills and the trout are feeding heavily upon them. The March Brown Dry size 14, Murray's Yellow Drake size 14 & 16 and Light Cahill Dry size 14 & 16 match these hatches. I have a few close friends that stick with nymphs even when the drys are on the surface. An excellent ploy is to fish a dry with a dropper. The Mr. Rapidan Soft Hackle (Brown) Nymph size 14 and Light Cahill Nymph size 14 are excellent nymphs to match these hatches.
The native brook trout streams are in great shape. For more information on the streams in the Shenandoah National Park--see my book Trout Fishing in the Shenandoah National Park which lists stream access and includes chapters on reading the water and hatch charts.