Having hiked in the Cascades east of Everett..
I have carried either a 4" .357 using 180 gr Hot cast lead or my 1911 using the last of my Hornady 230gr FMJ-FP commercial ammo. I have never had to use either, BUT I never felt under-powered. This in keeping with talking to the Sierra Techs, that I should use the heaviest FMJ at the maximum controllable velocity to pentrate and cause maximum damage.
The bears out here are the black bear, any grizz you might chuckle of how a "pleasantly plump guy can RUN!
The best defense it to keep your ears OPEN and eyeballs moving!