We have an even easier way to avoid bear problems. Avoid people. We never hike in highly popular backpacking areas, even in the Sierra, and we've only seen about four bears in the backcountry about fifty trips.

No, we don't hike the John Muir Trail much, rarely camp where the traffic has created enough problems for bear boxes. It works great!

(I'm only sort of kidding here--people are the problem, not bears. Avoiding highly trafficked areas really reduces any problems with bears.)