We are moving from Phoenix AZ to Minneapolis, MN. I have a moving truck with a car hauler and need to find a route that has the least mountains or lowest grades at the very least. I know we won't get the best gas mileage no matter what, but I don't want the absolute longest route either. Trying to get up the mountains with a 24 foot truck and car behind it has me scared to death. PLEASE HELP with any suggestions.