Can't believe you are putting up with this on your property, there are also liability issues if you let it continue. (I am an avid deer hunter and couldn't even imagine hunting on property that I didn't know the boundaries of) Collect his stand and leave a note explaining the reasons why and where he can claim it. Honestly, I wouldn't even be that nice, he knows he is not supposed to be there. If you are really serious and want to catch this guy trespassing, there are game cameras that are wi fi and will alert you and send and images to you real time. You can simply call the police or game warden when you get his image and get him red handed so to speak. (I have personal experience with this working)