I live in the U.P., well kinda, I grew up there and go back as often as I can. I live on the Western part where it sticks up into Lake Superior, Pretty much we ride where ever we want. But for Tourist up in that area there are recreation trails that you can ride on, and the further north you go up to our northern most town called Copper Harbor the better the scenery gets, the trails are probably a good 10' wide in most area's. There are some pits sand/gravel or whatever that you can ride on.
The people and the cops in the area dont really care what you do, riding on the roads or whatever as long as you are not acting stupid, speeding in town or whatever, the only thing a cop or DNR up in the area will stop you for if they are around is to be nosy, ask for some I.D. look for your ORV sticker and run your VIN to see if the bike is stolen, All you really have to do is tell them that you are from out of town and you are going to the trail, and more than likley if you are going the wrong way they will point you in the right direction, or they will let you continue on and laugh at you as you are winding thru the town looking for the trail.