I'm hard at work on my first real story and I've been curious to get some advice on this topic. The setting for my story is the eastern US, I never state that outright as I prefer to let the reader develop what they want to with the locale, but I do describe it in detail. My question is, for a Post Apocalyptic setting how much backstory is needed to allow the reader to reader develop a vision for the world? I don't want to be overly descriptive but I also don't want to just say "It's a desert" either. how do I balance the two?