As a person who grew up hunting and exploring in the foothills of Appalachia, and packed different handguns over the years, were I to choose a revolver as the OP stated, the 3" version of the S&W 360 would be my ideal choice. (Another poster posted a picture of one earlier in this thread.)
Full disclosure, I haven't had to actually use one on black bear, cougars, or the two-legged varmits, but I'm pretty sure a lightweight 3" .357 would work just fine.
I have no idea what all states the Trail goes through, and someone mentioned NJ, which reminds me of this Ayoob story:
http://www.backwoodshome.com/articles2/ayoob105.html about a lady carrying hollowpoints in NJ who nearly went to prison over the concealed weapon which was legal for her in CT, but not NJ. However, she got off lightly and was "only" fined $1000 per cartridge for carrying HP's.
