text: I don't know the 'by land' route, but at my work they just sent out an email stating travel to canada and mexico requires a passport,  the email states:\n\nNew 2007 Passport Requirements: \n\n \n\nU.S. citizens planning for their travel in the new year should be aware that effective 8-Jan, 2007 passports will be required for air or cruise travel to Canada, the Caribbean, Mexico, Central and South America and Bermuda. All children regardless of age (including newborns and infants) must have their own passport.\n\n \n\nhttp://travel.state.gov/passport/passport_1738.html