Interesting thread. After reading more information and replies, I am in a quandry. JohnBud has a real problem on his hands and it's difficult to swim upstream. It's like dealing with an oncoming wall of mud. I don't feel that physical force is the right way to go, either. This is a matter for the law.
Make sure you post your boundries/roads with "No Trespassing" signs. Then, after gating everything up and plugging holes, the cameras will do their job and the law will have to follow up. Too bad you don't have proof on camera about the ruts in the road...you could present them a bill for the dozer cost to repair it, to get the ball rolling. But you can get them with trespassing, illegal hunting and like 2ManyRocks said...a restraining order. (Good point 2Many). You need to be out there as much as possible to confront them and make your presence known.
It's best if you can have someone with you most of the time in case you are threatened...as a witness. These guys could try burning you out, but by then you have motive and a case or two already against them. You need to watch your back...and it's a dangerous situation already, since guns are involved with the illegal hunting. I would always be carrying. I would think the other landowners would be on your side since their land may be threatened as well. A person has a right to be left alone on their property, simple as that. It's like the wild west...
In this state, DNR has a program which authorizes their wardens to stop by and periodically patrol your property at odd times. This is above the normal routine duties they already do...poaching, etc. You fill out some additional paperwork, give them a set of your keys for entry, a boundary map, and you authorize them to arrest anyone without written consent. You also give DNR your list of authorized people and they make it a point to pop in and out when they are in your neck of the woods.