Reader Mike Stein, another Nevadan, suggests:

How about Afganistan? It is about as inhabitable as the Moon and somewhat closer. Wasn't there a cave complex that withstood continuous bombing by our best conventional arsenal? Just a thought.

Well, if we can pay them to not grow poppies, why not this? (BTW, I wonder how much I can get paid to not grow poppies? Or corn? I can not grow stuff with the best of them...)