Originally Posted by
mattm00se
the OP is fine in this case (US citizen), but just in case anyone finds this thread in the future, it's unlikely any airline will board you without a a canadian visa if one is required (even if you're connecting to the us), since I don't know if any airline considers this 'real' sterile transit.
I could be wrong, though..can anyone confirm/deny?
Correct. Only "some" international to US passengers do not require to clear CBSA before clearing US CBP inspection, according to information posted at the GTAA web site.
http://www.gtaa.com/en/travellers/co...nnection_tips/