They say there is a big difference between grizzlies and black bears, and different strategies in dealing with the two types, but in Canada, I saw a blackie as big as any grizzly. I would definitely fight a black bear, and if I didn't even have so much as a knife, I would try to bite its eye out or its nose off or something like that. I think I would play dead with a grizzly, even if I thought it was hungry, until I was certain that it would eat me, then I would take as much of its eye or nose with me as I could. Don't put yourself in a position to where you have nothing to defend yourself!!! Rifle, shotgun, handgun, pistol, pepperspray, knife, firecrackers, whatever works, carry what you believe to be most effective. Research, read, study, talk to those with first hand experience, and prepare, prepare, prepare !!! Go in ready, stay aware at all times, expecting the worst, and sleep with one eye open.