I'm from the very southern end of Appalachia.
Some things I would consider essential to capturing the mood of the region, in a D&Dish fantasy context, in my opinion, would be:
•The forests are dense. This is something that people who haven't been to the region won't understand. The trees aren't often very large (poor soil), but they grow nearly as close together as grass in a field. Between the thick foliage and the mountainous terrain, a laden party of adventurers on foot will be lucky to travel 4 miles in a day.
•Everything is isolated. In a fantasy setting with no highways or telephones, you can really play this up. Towns are far apart from each other. There are homesteads sprinkled across the mountainsides many miles apart, sometimes populated by families who aren't aware of their nearest neighbors' existence.
•Hospitality is important. It's not like
Deliverance. If strangers come to your door, you let them in, you feed them, and you find out what their story is. There aren't going to be a lot of inns for the party to rest in between towns. They'll need to either camp out or rely on the generosity of whatever locals they meet.
•That said, don't abuse your host's hospitality. Everyone is armed. In real life, that means a lot of people enthusiastic about the 2nd Ammendment. In a fantasy world where you probably don't have guns, I might have some NPC's who are proud of their old family sword or axe.
•Farming sucks. Poor soil. Hunting and fishing are comparatively efficient ways to feed your family.
•There are a lot of caves, and the caves get pretty big. There are also ruins, of a sort: abandoned homesteads, bootleg distilleries, and mines. Plenty of places that could become dungeons in a world with monsters.
Please for all that is good and holy, just promise me that you will pronounce it properly: "apple-at-cha."
Sincerely,
An Appalachian Native
Hear hear! The "i" is silent and the "t" is invisible.