Give it up. You'll not find anyplace in the USA that isn't private or government land - "public land" is government-owned. If you're caught "living off the land", you can be charged with trespass, with molesting wildlife, with damaging protected plant species, and with polluting the environment by taking a leak or a dump in other than a facility specifically constructed to cleanly dispose of human wastes. Yeah, some people sometimes take a dump in the woods and get away with it: but you'll eventually get caught, and the penalties can be painful.
