RE: To ATV or not to ATV, that is the question.
As you describe, it sounds like the area we hunt in. We use ATV's to get to the trailheads. Only areas we pass on them is other camps. They are usually dark as we pass by and I can't help but think they should thank us for letting them know it's time to get up.
Like most things...just follow the rules and there is no problem. The mostly two track roads we take ours on is also used by pickups etc, especially the local folk that tend to be in the back of the pickups with guns in hand.
And if you see or encounter someone on one in a prohibited area...let the authorities know. We do. Ruins it for all. Never had a problem with anyone messing with an atv while elk hunting. The vast majority of men that go to the time and expense of such an endeavor are of sound moral fiber. But you can be sure there are always bad apples. As someone mentioned earlier, sure would be risky to be messing with someone's atv, not knowing if he is sitting up on a hillside watching you through his scope?