I don't know about SE PA but in SC PA in the Michaux State forest we have loads of wild lowbush (well at the leaset they appear to be lowbush because the deer don't let them grow very much) blueberries. But the deer & birds eat them, I don't bother. But they are all over our woods.

From the USDA map, it looks as though it grows in most counties.

Here is a link that might be useful: Vaccinium corymbosum

I've seen them in the Lehigh Valley. Rare in exurban areas, fast disappearing. They like wetlands, also fast disappearing.

I agree with pinkmountain. I used to see nice patches of blueberries along the local stream when I was younger. Now the very same area outside West Chester is home to a golf course and Toll Brothers mcmansions. I doubt they are there still and I'll never know since it's private land. The farmers that used to keep up the land used to wave when they saw you out there. The golfers on the other hand ... well two of them threatened to do me bodily harm with there clubs right in front of my 8 year old daughter while I was walking the woodline with her.