Public land is public land. Just because there is an empty stand there doesn't mean that you aren't allowed to hunt there too, just use good hunting sense like watching the wind, etc. If the stand is occupied, by all means, move on. Most public ground in IL allows a hunter to leave one stand hanging and many of us do that, and just carry their climbing stuff in. It saves the time, noise and danger of hanging and pulling a stand in the dark. It is NOT alright to sit someone else's stand without their OK. If I catch someone hunting from my stand, I'll not get in a argument about it, I'll just pull the steps and leave.