I've come across many black bears in PA. They usually pick up your scent and go out of their way to avoid you. One time at a lake I was discarding some garbage in a dumpster when I saw two cubs sniffing around just a few feet from me. I immediately looked around for their momma, and found her about 20 feet away, giving me a look as if she were saying, "Hurry up, do your business and scram."