If I was going to hunt with a side arm in bear and perhaps mountain lion country, it wouldn't be with anything less than a 44 magnum in a revolver. Sure, in ideal conditions the 357 will do the job but how many times have we fired a shot at game in ideal conditions? I wouldn't want to track a wounded animal either in bear and cougar country with nothing more than a 357 magnum.
The northern tier states are becoming more populated with dangerous game and there's nothing worse than being under-gunned at meal time. Just my .02!