I've been hiking and camping without ever having any problems with bears. Most bears I've seen were scampering away very quickly.

National Parks are a bit different as the bears get so much human interaction that they loose the normal fear of humans.

I did find some boats up in the mountains that someone had tied in a tree. 1 rope between two trees, with the boats hanging from the middle. The highest one was just fine. The lowest one, the bears used it like a tetherball. Needless to say, while the boat remained tied above the ground, it no longer appeared to be airtight.

Someone had the bright idea to reintroduce the Grizzly to one of my favorite hiking areas in Northern Idaho, but it has been a while since I've been back there. Otherwise, there are very few Grizzlys in the USA. Yellowstone?

The black bears in general aren't aggressive, except maybe in the national parks.