If I had 40 million dollars to invest in a place, in Appalachia, it would be southern West Virginia. I have seen how rough things have been over that way since the coal industry has all but disappeared, which left tons of people without jobs. So if I had that kind of money I would probably build some kind of massive resort like the Greenbrier or something along those lines.
image taken from: http://www.gvairport.com/greenbrier-valley-area-info/attractions/the-greenbrier
West Virginia is a beautiful part of the country, there is an endless amount of attractions you could have at a resort. You could have activities that stretch from golfing to snowboarding and everything in between. A resort would have an absolutely huge impact on a community. The job opportunities would be endless for people in the region. Not only would the resort do well but it would bring in so many other people so other businesses would also thrive.
I would also use the money to set up scholarship funds for kids of the region. That way if they worked hard they would have hope of going to college and making a better life for there self.