The northern most part of the continental USA is the Northwest angle which is the only part of the country north of the '49th parallel. I learned this back in grade school. Northwest Angle The residents have to drive through southern Manitoba to get to and from their property. I'm a little surprised you Americans are not more aware of this tidbit. It a bit like learning that to get to Detroit you have to go NORTH from Windsor, Ontario. Or finding out that the border along the '49th parallel isn't a perfectly straight line but wobbles in a very minor zig zag by as much as a few hundred metres. (Original surveys were not as accurate as today's GPS systems.