Lewis and Clark had to shoot at the grizzlies a lot.
You see, they had gun nuts even back then, just as we do now. They just didn't post as often.
Oh no! Someone said something that offends me. I better start a 30 page thread on how upset I am.
EDIT - Just to add something somewhat valuable to this thread... Polar Bears are supposedly more aggressive towards humans than Grizzlies.
Having spent a decent amount of time in Alaska, I've had countless run ins with Black bears. I've even been bluff charged. I never want that to happen ever again. She got close enough for me to pucker up a bit. Ha! :D On another occasion, our group had a bear visit our camp at night. He/she would come and go throughout the night. I don't know how close he got (dark), but I could hear him and that was close enough. I'm always careful with my food, so I don't know why he was hanging around.
That said, I've never really had any real problems from bears. Make a little noise and they stay clear. Most people worry for no reason. In Alaska, you have a greater chance of getting killed by a Moose than a Bear. YMMV.