I would report any signs being put up to the owners of the land, be it state land, federal land, or??
as legally its NOT allowed to do so,
However, many public lands ARE land locked, meaning you HAVE to cross private lands to enter the public lands and, land owners have every right to post and NOT allow folks to use there land
SOME state lands have easements, but NOT all do
so, are you 100% sure its truly public lands where the signs are?
so again, report it if so to the right authority and if it is truly public, you have every right to be there as anyone else
BUT this also doesn't;t mean you can take over any spots you like or find, its a free for all on public lands
ONLY real rules I seem to find, is HOW the person was raised , if they are more kind and not wanting to sit next to you or use you as scouting tool cause there too lazy
or how ignorant or NOT they are, which again, seems to me to come from how they were raised and there morals they have or don;t!