I just gotta toss a comment on the pile. No knife is a good weapon against a bear. Bears are bigger, stronger, and faster than you... and they come with 20 claws and some number of fangs. The best weapon against a bear if you must kill one is a stout rifle, followed by a 12 gauge with slugs, and distantly trailed by serious handguns (.44 magnum, .454 casul). Even if you manage to kill a bear with a knife, you're going to take damage in the process, and it will likely be your end.
Of course, simply being alert and seeing the bear before it sees you (bears are not, by nature, subtle creatures) will prevent a situation from developing. Snakes, now, they are sneaky bastards. I don't have any snake experience other than watching them zap into the grass with startling speed as you're about to step on them.
Yes, this is well understood. I live in bear country, grew up in it. I have brushed off many with brooms, etc. They are common in my yard, often eating from my blackberry bush. I am a field geo, with 30 yrs experience working in boreal forests. I would say your firearm reccomendations are good for a textbook, but not so much real life. I usually carry a sporterized m-14 with a 10 or 20 round box or a benelli auto shotgun. Good luck trying to hit a charging bear in 1-2 shots with a cannon. No I don't live in the lower 48. It has been my experience, that they are often quite subtle and playful. Spend any time near a stream with a salmon run and they appear out of no-where with great stealth. I cannot tell you how many I have "stumbled upon" or have nearly bumped into me. Bluff charges are common.
It is often hard to carry a firearm in foreign countries. Many bears have been killed or fended off by large knives. Firearms are great tools, but it pays to have a decent blade. I have been using a machete from cold steel. Hoping for a return of dogfather I suppose.
