Today I walked two trails in the Laurel Highlands. Camp Run isn't worth mentioning (few birds) but I had a good time on the Blair Bros.RR Grade Trail at Hunters Lane.
Best birds on the RR Grade trail were an olive-sided flycatcher at the wooden bridge, two ruby-throated hummingbirds that perched near each other without fighting (!) and a small flurry of 6 warbler species. I also heard and saw an immature rose-breasted grosbeak practicing-singing.
The complete checklist is here:http://ebird.org/ebird/view/checklist/S39093351