I live in the Sierra foothills. I don't have a real bear problem since I move closer to town. Where I used to live was right on the American River cayon. Hardly a week when by that I didn't see a bear, but they didn't cause a real problem. That is until the retirees from LA and San Francisco moved in. They never put the garbage up or cleaned their BBQ. That is when the bear lost all fear of humans. I will tell you this, if a bear wants in, it will get in. Short of a coop made from 1/2 inch steel plate, with no place for it to get its claws in. If you see a bear come around twice, kill it. For it will continue to come back until there is no more food for it. In Ca. the Fish & Game Dept. will give you a permit to kill any predator that goes after livestock. And you do not need this permit if you are in immedite danger.