I also vote for the Buck and Rail fence. Not too offensive to look at, easily repaired. Sure, it will get torn down by a-holes from time to time. But, every one of us who wheels out there could take a few minutes and repair it when it happens. Maybe after a while people would get the hint and leave it be. Maybe in conjunction with some signage and some revegetation behind the fence it would become effective. It's a place to start. The trail is going to take some maintenance to keep it close to the way it was intended to be. I'm willing to step up and do my part to help out.