Had something very similar happen to me.

Pulled up to the public ground I was hunting and there was someone that works for the farmer that owns ground that borders the public ground on two sides. And he is the largest land owner in the county we live in and is an ass to boot.

Guy drives the tractor up and get off and says you are on private ground. I said no I am not. Then he says well this is a private drive and the old river is the access and again I say no I am not tresspassing so I get the maps and GPS out and show him that I was in fact on a numbered county road that was unimproved. He still keeps on at me so I look at him and say I'll tell you what you call you boss and the sheriff and I am going hunting and I will be out at around dark then we will go from there. He looked at me with a stupid look and said I will have to talk to my boss and I repeated what I was going to do and what he can do and really I was daring him to do because I knew I was right.

It's the same old BS all the time with land owners like that. Alot of people don't know this which I guess is good for me but I just hate it when they try to keep even public ground private through lies!!!

To OP yeah you where a little harsh but you have to stand up for your rights cause they will walk all over you if you let them.