Great Lakes Car Ferries
 

We have decided to drive, to see the sites, from Las Vegas to Montreal. Has anyone done this? Or part of it? We are thinking of going through the great lakes on a car ferry. Is this possible? I cannot find anything on Google.

There is a car ferry that goes across Lake Michigan from Milwaukee WI to Muskegon Michigan. http://www.lake-express.com/
I doubt that you can get a one way car rental from Las Vegas to anywhere in Canada.