I think you may be allowed to drive a short distance off of the road for game retrieval, but I can't remember how far exactly.

In all honesty, though, it'd be best if you just stayed on the roads/trails. There's a real problem here with irresponsible ATV users going off of the trails and tearing stuff up. They give us all a bad name and if the idiots keep it up they're going to ruin it for everyone. I'm not saying you're irresponsible- I just think it's better for everyone if ATV's stay on the roads/trails. There are more than enough ORV trails to get you in the general area where you want to hunt (get a free ORV map to see all of them), and some of them are plenty rough if you're just looking for a challenging ride. Besides, deer don't weigh that much. Dragging them out isn't that hard if you just halve them.