"Black bears in the Southeast mountains are a concern and the handgun would be a last resort. There are just getting to be too many black bears that have lost their fear of people due to hitting trash cans, picnic areas, garbage dumps, and other places where humans hang out and have food."
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Same situation here in north GA mountains. Three women have been killed near here in the last couple of years and one child was badly mauled, all by black bears. I don't bame the bears, they just act on animal instinct. I blame the people, usually from Atlanta, who carelessly leave food and fish heads and entrails at the many camprounds, fishing streams, and roadside picnic tables in this area, and also the local people who leave stinking garbage in their yards where bears can easily find it. I have had a full grown mother bear and a cub in my yard sniffing around the barbecue pit before, but I stayed in the house until she decided there was nothing there to eat and led the cub off into the woods again.
I live way out in the hills, and when my wife and I take our daily walks on doctor's orders I used to carry a little Beretta .22 pocket pistol just in case I ran across a copperhead, rattler, or rabid small animal. I killed a coon and a possum with it that were both acting very strangely, but I don't know if they were rabid or just very sick with something else. The county wildlife officer said there were a lot of coons and other small animls sick in the woods that spring due to the unusually wet and cold weather but were not rabid.
But after a pair of very agressive Rottweilers from out of nowhere recently treed an electric co-op lineman for a few hours on a power pole just down the road from here, I started carrying a model 66 .357 mag instead. There are also plenty of half crazy meth cookers in these woods nowadays, so I carry it loaded with 158 grain Hydrashoks and also carry a speedloader full of my 158 grain hard cast SWC reloads which I figure will take care of any 2 or 4 footed varmints in this neck of the woods if I put them in the right spot. A really big boar bear with an attitude would be harder to stop than anything else around here, but I think 6 of those SWCs would do the trick if I wasn't too scared to put them in the right place. A.41 or .44 mag would be much better for that purpose, but the chances of being attacked by that big boar bear are so slim that I'm willing to gamble on the .357 doing the job if that very unlikely attack ever takes place instead of laying out $400-$500 for the least expensive .44 mag I can buy around here. I have shot my friend's Anaconda occasionally but I don't really enjoy shooting it enough to buy one.
But for a trail gun in MO I think a good quality 4" medium frame .357 revolver carried with full house hard lead SWCs in the cylinder and a speedloader of .38 sp wadcutters or snakeshot rounds in your pocket or backpack would fill the bill quite nicely. If you have reason to fear a run-in with 2-legged predators in your area, a 2nd speedloader of 125 grain .357 hollowpoints might not be a bad idea. These are just my thoughts on the matter, and I'm no expert so take it for what it's worth.
I realize that my two revolvers aren't the best for the trail. I do have a SA GI 1911a1, a CZ 75B, and Makarov. Again, none are ideal IMHO. 
