And just an addon to that - I *never* see black bears up high - only grizzlies - so if you're considering where you do and don't find black bears in the sierras, don't make that correlation with grizzlies.

(of course, for all I know black bears might go up high here too if it wasn't for the grizzlies - they kill black bears as direct competition and the black bears avoid grizzlies)