Although I am a big fan of the Blackhawk (and SBH), in my opinion a SA revolver would be a poor choice as a bear gun.
The Redhawk in .44 is an excellent choice, with ammo readily available and .44 Specials can be bought for practice. I'd opt for a stainless one, especially for carrying in the mountains where the weather can be unpredictible.
The standard 5.5" barrel is a good length that allows for comfortable shooting without being a mile long, just find a good holster that allows easy access and your set!