Welcome to bear country! I'm in the middle of a war zone up here in CO as well. I had a bear break in and kill all 45 of my chickens about three years ago. I got three llamas and that took care of the problem for years, at least until last week when a mountain lion jumped in and killed about a dozen of my largest birds. Apparently llamas won't work with lions. So for the past week I've been locking the llamas in my livestock trailer, locking the chickens up in the bear proof coop, and locking my baby calf in the garage. I've just installed an electric fence and put everything back in the round arena.
Here's my security now: I have a round arena that is about a 1/4 acre, surrounded with horse panels and on the outside of the panels I have six foot chain link fence. And on the outside of the chain link I have two strands of electric wire, one about knee high and one about nose high. I bought an 18 joule charge controller, plenty of power for those thick furred critters. I also bought four 'night eyes' blinking lights, not sure how effective they are but everything helps. I also have the three llamas that protect most of the time. I've also decided to lock up the chickens in my bear proof coop every night, that seems to take the food out of the picture since lions and bears usually come around at 3:00 AM or so.
The reward for all of this is that I can run my 100+ chickens in the arena all day long! They are very happy birds!