I beleive you still can get othrough with just birth certicate and dr. licence . But soon USA will require passport. It's easy getting in but getting back our guys are murder, no goofing around they are very serious. Had one customer last summer didn't beleive me they held him and family 3days and he was a US citizen he cracked a joke . can't remeber what but no fooling around. You going to go through Montana? I live close to the border.