Originally Posted by
Kevin AA
Canada is a foreign country.
The entry requirements are different and it is possible for a Canadian to enter the United States without a passport.
https://help.cbp.gov/app/answers/det...-residents-%2F
Canadian citizens traveling to the U.S. by land or sea are required to present one of the travel documents listed below, and may generally visit the U.S. for up to six months. CBP will accept: Canadian passport, Enhanced Driver's License/Enhanced Identification Card, NEXUS, FAST/EXPRES and SENTRI enrollment cards.
It's quite common for Canadians to drive into the U.S. and then take a domestic flight from an American city. It would be quite possible for them to use an enhanced driver's license to enter the country.