I'm no authority and it may not be worth it anyway to have the conflict, but I live in an area where the roads are called "Private with Public Access". Meaning that both sides of the road are private property, however the road is not "County Owned" yet public access has been established. I think you can go to the County and find out how the roads in that area are designated.
Most likely they are just putting out the big scare to get the reputation it's a "no fly zone". But if it is designated as Public Access, there is nothing they can do.
I tried to put up a gate on a public access road where I lived at the time that dead ended into National Forest. Little did I know that it was a "not so secret" trail for moto's to shortcut. Even though it was "illegal".
One day I was fed up as some moto's came flying through my property (about 100 feet from the house). I fired a shotgun in the air just to try and start the "no fly zone" rumor. Naturally that one time it was some local kids that I scared the hell out of. Parents came over screaming. I assured them. Kids got in trouble, and the sheriff showed up. Did not get in trouble for the shotgun event, yet he told me I could not put up a gate on my own property even though the road ended at the end of my property at the National Forest Boundary line (150 feet?). The dirt road went through the middle of my property and all I could do is call the cops as the Moto's went by (good luck!) It wasn't even considered trespassing! Yeah, this is my life :wave:.
The short of it, if they are hateful enough, they will just boobie trap the trail and someone will get hurt. May not be worth the effort....