MilesBuzz! - YYZ-ORD-YUL, immigration proceedure?

A friend and I will be on an AA award ticket in October which starts in the US, goes to Canada and ends at JFK again. Since there's no AA flights YYZ-YUL, we will be flying YYZ-ORD-YUL with a 2 hour layover in Chicago. We both have Swiss passports.

What are the immigration proceedures for non-North Americans between the US and Canada? Is it a shared area (like e.g. Scandinavia) or do we have to immigrate / leave (including filling in the green forms) every time we cross the border? Or would at least the YYZ-ORD-YUL flight be considered "transit" and not require US immigration?

Thank you for your advice.

------------------
airOli (http://www.olimade.com/airoli), the Swiss Air Line. ;)

you will have to immigrate to Canada (no transit areas, keep the green US immigration card and show it again at reimmigrationto the USA), reimmigration to the USA is done already at the Canadian airports, after check-in.

Showing your through ticket when exiting Canada (as long as it is no Canadian stopover) you can avoid paying the Canadian airport tax (otherwise you have to pay in cash).

This is not a mileage specific question, rather it is something appropriate for "TravelBuzz". Please follow the thread there.

------------------
Craig6z
Buzz & United Moderator
moderator2@flyertalk.com