if you park where they can see you yes it is illegal. if you ride where they can catch you it is illegal. if your a smart a$$ to the sheriff he will impound your bike and write your truck a vehicular trespassing ticket.if your calm and respectful with the sheriff he will probably tell you to leave with a warning. if you park in the back and dont ride right next to the hwy you can most likely get away with it. it is at your own risk tho.
Yea it is illegal forsure. But like everyone else said. Drive kinda far back and find a turn off that goes inbeetween hills (most are dead ends) go a little far back in there and your most likely not gonna get caught