I grew up in Park County, Wyoming. Many backpack trips into the Bighorns for trout during Summer and mulies in Fall. Black bears are common and some of them do not have good manners at all.
I always carried my antique Iver Johnson shotgun in 16 gauge. Kept her loaded with a big fat deer slug for educating rude bears. But in all my travels, I was never attacked nor threatened by bears. However, its best to follow the Boy Scout motto,
"Be Prepared".
TR