I am not a legal expert by any means, but I think it should be allowed, I mean out of state boats can freely access the lake. That with the addition that the ATV is not licensed/tagged (but that is the state of Ohio). I would think it would be fine, assuming that they stay in the US part of the lake, just like the boats if they cross over to the Canadian side. Just be careful no matter where you go and what kind of vehicle is used on the hard water.