One outdoors gun?
Since most of the time I'm here on the east coast, or possibly in the midwest (the furthest west I routinely go is Minnesota), I'm looking at black bear and occasionally moose as my worst possibilities. Until I go camping further west, I'll go with a medium framed .357mag. A K-frame or L-frame (or GP100) will even handle the bear strength loads with reasonable recoil, while still being quite manageable for carry. I don't hunt so walking around with a shotgun or rifle in my hands just wouldn't be very handy as I go about my business while camping, walking or kayaking in the woods, and slung over my shoulder, it would likely be much slower to get it on target than drawing a revolver from a strong side holster.
When I take a summer for a cross country camping trip (I'm a teacher and off summers, or will be when I stop teaching summer school), I may change that up to at least a .41mag and more likely a .44mag in a 4" N-frame. My .45LC 625MG is doable, but a little large for all day carry if grizzlies aren't a possibility and standard .45LC may be a bit under powered for grizzly (though when outdoors when someplace where very large black bears are possible, I sometimes take it). In grizzly country, if I went .45LC I'd probably want a Ruger for the "Ruger only" loads from Underwood or Buffalo Bore.