I know you are waiting for an official response but here is my input.

1. Shooting on your own property is not against the state law.
There may be certain town ordinances but not state laws.
2. Driving the UTV on the road is against the law, but if he does not drive that then he will drive a vehicle down there and or park a trailer on the side of the road unload the UTV then go into the woods.

The really only shot you have is if he is running pistol courses and charging people to take the course and then shooting he may now have a "shooting range" that would have to have some safety measures put into place. Which may be to costly for someone to do who is just doing this part time.

When ever you deal with him be polite and talk nice never reveal what you are doing about investigating this, I probably would not even tell the neighbors until you have rock solid info.

Hope you get an answer and sometimes it's not always the one you want.

We all want our freedom and want to be able to do what we want on our own land and sometimes that means having to deal with others doing the same.

Good luck.