Somewhere or other, Bill Bryson describes pulling up to a service station in a deserted region, and being attended by someone of (I guess) an in-bred community or something, and the sinister nature of the whole encounter freaked him out. I'm sorry I can't be more specific but I'm writing from memory. Maybe I'm mixing up the Melungeons with some other group? But it was told as a first-hand experience where he was driving in a remote area. The whole atmosphere of the anecdote was quite creepy.

Clarification, anyone? I know I read this - but don't have it to hand to quote from. (Please don't make me spend all night tearing through a zillion boxes of books...)