A friend of ours barely survived a grizzly attack. It wasn't exactly unprovoked. He was bow-hunting (which most people can't believe) and took a shot he shouldn't have. The bear was on him in a flash, opening him up and taking off some body parts. Even though he lost part of his right hand, he managed to get his .357 mag out and emptied it into the bear before he passed out. His hunting buddy heard the revolver and got to him in time to keep him alive. Then they managed to get him out of the woods and flown to the right hospital(s). All in the days before cell phones.