limoshawn - 4:47 pm on Dec 10, 2008 (gmt 0)
we were rv-ing in Montana (Glacier National Park, I highly recommend it) about a year ago and decided to rent a car and go to Canada for the day. It was a wonderful day in a great part of the country.
Upon our return to the border we quickly discovered that we should have put more thought into what we would need to get back into the country! Turns out they wanted to see more than a drivers license and a hi-de-ho good neighbor! They kept us there for hours grilling us about where we were from, why we went to Canada and tearing the rental car to pieces! eventually they let us back in. If we had taking our passports there would have been no problem at all.