We have problems with snowmobilers and atv'ers. It's the same guys, they just trade one form of racket for the other, depending on the time of year.
There should be a bounty on them. Shoot them, skin them out, and nail their hides to the barn door as a warning to others. They rip up and down our property line, right along "the trail" (that they illegally put in). But they also rip up and down our driveway, through our yard, chase our livestock, tresspass in the field behind our house, rip all the "no tresspassing" signs down, pulled down a section of fence blocking off one field, rip past our house on both the trail side and on our private property side late at night, with open exhaust 2 stroke "race" snowmobiles (aka LOUD).
The atv's rip up our grass, both in our yard and in the pasture south of the house (since they've torn down the fence, and torn down all the "no tresspassing" signs). They do donuts in our gravel driveway, and generally make as much nuisance of themselves as they possibly can.
They do the same things around each of our neighbor's places too.
Put a bounty on them.