I have been reading the responses to your story with interest, amusement at times, sympathy but most of all concern. While I initially respond as a lay person just like many here on Ridecamp and think of guns, the posse and large dogs as companions, as a lawyer I must temper those responses with serious reflection.
First, assume these people really are wackos----and there are some out there----I would hate for you to be "dead right".
I share Steve's opinion that the sheriff's position is uneducated. Many police officers, particularly in small rural areas, are limited to a high school education and 6 weeks at Peace Officers' Standards and Training. You are being way to nice and way to quiet about this. I know Idaho has a victim's advocate----find the phone number from the local court clerk and call for help.
I would also insist that every incident be written up and documented at the Sheriff's Office and I would take each police statement directly to the office of the appropriate prosecutor. I doubt any attorney would tell you that the actions of these people were not criminal. I can think of a dozen local ordinances that could be used to send a clear message and most prosecutors would look harshly on such potentially dangerous conduct from property owners.
Additionally, I really do feel you should seek the advice of Idaho counsel, as I suspect one letter from an attorney to these people and the Sheriff's Office, advising of the real status of the law would not only make the property owner back off but also bring to the Sheriff's attention his responsibilities to you. I also agree with some of the other suggestions about support from other riders on horseback but why not seek help from the trails people in your area. If this is a deed public access, then you do not need permission and should certainly not be explaining your presence on the road to anyone. Instead, invite public access users to show support by using the road regularly for all kinds of lawful purposes.
