There were three grizzly attacks last year in Montana alone! None were fatal but I'd say that comes down to luck more than anything. One was a college kid rushed from behind by Ol' Grizz- knocked the kid flying into a tree. By some miracle he was able to retrieve bear spray from his backpack (!) as the bear was on top of his back; with the spray he was able to drive the bear off.

Playing devil's advocate and living in two states with a lot of bears (black and griz) I will tell you flat out that a lot bear attacks and aggressive bear encounters are never reported. In ID and MT they call it the 3 S's (shoot, shovel and shut the heck up).

There was a meta-analysis a year or so ago that wasn't so favorable towards bear spray. I will see if I can find it. It seems that as humans and bears have more contact the bears are learning that the spray is painful but not debilitating. There are a couple of well documented cases where black bears stalking humans were run off by spray only to return repeatedly when the spray began to wear off. And the guide in CO killed by two grizzlies had spray; when game officials shot the bear to death its skull was saturated with bear spray to the point where it was dripping off. The guy was still killed.

I will continue to carry bear spray but I will back it up with lead spray since that's legal here. I suppose each of us will have to determine the risk themselves. To me it's not so much the odds but the stakes. Plus, I would feel naked without a firearm in the woods!