You got some good advice so far so I won't repeat it, but to answer your question I have had two close encounters with bears one in NH where I have run across 6 or 7 over the years while backpacking and one in Alaska. The rangers at all the NP and NFS CG's that we visited always told us to make your self look big and yell when confronted by a Black bear. It worked in NH but when I was fishing on the Russian river in Alaska a large black bear came to the pool where I was fishing about 30 ft away and the river was about 2 ft deep, I raised my arms over my head to make myself look big and yelled "Hey Bear get out of my pool" he stood up on his hind legs and just growled at me, so I moved down stream to the next pool. Like any wild animal I think they are unpredicable. In TN where I camped one year they don't hibernate so they get real big, and several people were killed by Black bears while camping.