Wait wait wait. So you're saying to start the story when the invasion starts? I was originally thinking the invasion happened about six weeks prior, and these guys up in the woods are basically refugees after the fact, a la Red Dawn. But if I do it your way, the aliens have managed to land in the backwater, established a beachhead without the rest of the world noticing? Like Heinlein's Puppet Masters?
That's extremely interesting. And Appalachia would be the perfect place for such a beachhead. We have ZERO military installations, the population is sparse, isolated, insular, and we are so off the radar of the national consciousness that you could set off a nuclear device here and nobody would pay any attention. But despite all that, we're not a day's drive from the Capitol, within a day's driving of half a dozen military bases, less than a day's drive from at least five major metropolitan centers (Atlanta, Cincinnati, Chicago, Nashville, St. Louis).
In other words, the perfect spot for a quiet little beachhead and launching-off point for in-depth recon and intelligence gathering.