I'm very pro "self defence" and I own a few defensive firearms for home protection and maintain proficient use in them. You could say I am a gun-guy.
The first step is making the promise to yourself to never willingly become a victim, self defense is a mixture of mostly mental preparedness, maintaining situational awareness of what us occurring around you, a little bit of dark intentions for any thing or person that means you harm, and lastly having a weapon or means to project physical force upon those who would harm you.
Now all that sounds pretty gung-ho, but avoidance and de-escalation is the name of the game. Hikers tell you about the tweakers at a shelter, bypass them and stealth camp elsewhere. Rangers posted signs at the trailed about problem bears? Hit another weekend loop somewhere else. Hike up onto a grow op/meth lab? Beat feet outta there!
Onto hardware: what you carry is a function of threat assessment vs your visible profile vs weight. Not enough weapon and your unable to project stopping force, too much and you risk scaring passers-by, maybe getting the police called on you. Likewise too much and youre weighed down.
If profile and weight weren't factors, we would all stroll out into bear country with RPG's or belt fed lmg's. But they are.
If you're worried about bears only, bear spray is the most survivable option. Alaskan police have done studies. Handguns (including magnum revolvers) offer negligible protection, large caliber rifles and 12 gauges give you about a coin tosses chance of survival, bear spray is like 90%+ survival rates in attacks.
If you're worried about people, a big gun can be a deterrence, or it can be an object to steal from your dead corpse, and this is why profile is equally important as stopping power. A full power modern handgun like a glock in 9mm, .40 or .45 is enough gun for a person or black bear, and can be carried in accessible fashion without drawing too much attention. You can also get some bird shot cartridges that will open up survival hunting options.
Whatever you carry, practice is everything. You must be able to rapidly deploy the weapon and engage the threat, or you may as well leave it at home.
For my needs I chose concealable pepper spray. Will put a person in the dirt, and I can flee the scene without informing any police, or leaving a body count (maintaining low profile), legal in more areas then the firearm, and easy to dispose of if you're in an area with questionable legality. Buy more online if you need it, get it shipped right to you at a supply point.
Good police grade pepper sprays will have a more potent mixture then bear spray formulas, so it will perform double duty. I'll return later with some links to suggested products.