A very effective technique for trout is dapping a dry Inchworm along the undercut banks and on the shaded side of large boulders in the stream. Try to make the Inchworm dance delicately on the surface of the stream just like a real one suspended on its thread spindle. I have been doing well with the Murray's Inchworm size 14, Murray's Flying Beetle size 16, and Mr. Rapidan Ant size 16. These are equally effective on the brown trout streams and the native brook trout streams. Fish these on a Classic 7.5ft 6X leader.
Earlier this week the water temperature in the Shenandoah National Park at 10a.m. was around 64 degrees and the native brook trout were feeding well. The streams are starting to get low so the trout are wary. Be sure to hide your approach and if needed, get on your hands and knees and sneak, sneak, sneak.
If you need help on stream access to the Shenandoah National Park, stop by the fly shop or see my book Trout Fishing in the Shenandoah National Park. This is a great time to camp overnight so that you can get two days worth of fishing in but be sure to follow the Parks regulations which includes no open camp fires. Be sure to clean up all trash and take it home with you.