Here in Michigan, the law for operating a sled on any land other than your own is the sled MUST have a working headlight. However, I have seen many times an old sled from say the early 70's with a really dim headlight but it was "working". I would guess that as long as some light is coming thru, you would still be legal. The Mi. DNR website has all info regarding sled operation on and off the trail.