Originally Posted by
gglave
How did you manage to exit the International concourse? Typically the only way to exit is for a staff member to lead you to Canada Border Services to have you processed through Canada Customs.
Passengers on arriving flights can make their way to US preclearance but I'm genuinely curious how you managed to go from wandering the duty free shops to accessing US preclearance?
Through the US Connections Facility. Basically there's an entrance from right behind the D-gate security that goes into the US Preclearance facility. You get there from Canada arrivals by walking through the long corridor that's shaded both blue and green (behind the int'l ticketing).
Connections Map - Canada Arrivals