Since early 2007, I thought a passport was needed, but according to this, they may not be:
[From CBSA publication, bsf5082: Visitors to Canada (modified 2012-12-05)]
When you enter Canada, a border services officer may ask to see your passport and a valid visa (if you are arriving from a country from which one is required). If you are a United States citizen (U.S.), you do not need a passport to enter Canada; however, you should carry proof of your citizenship such as a birth certificate, a certificate of citizenship or naturalization or a Certificate of Indian Status, as well as a photo ID. If you are a permanent resident of the U.S., you must bring your permanent resident card with you.
So, this might mean that my American friends that have been saying "Oh, we'd really love to come visit Canada, but we don't have a passport" can visit after all?
Is the passport, an airline (or commercial carrier) requirement only?
[From CBSA publication, bsf5082: Visitors to Canada (modified 2012-12-05)]
When you enter Canada, a border services officer may ask to see your passport and a valid visa (if you are arriving from a country from which one is required). If you are a United States citizen (U.S.), you do not need a passport to enter Canada; however, you should carry proof of your citizenship such as a birth certificate, a certificate of citizenship or naturalization or a Certificate of Indian Status, as well as a photo ID. If you are a permanent resident of the U.S., you must bring your permanent resident card with you.
So, this might mean that my American friends that have been saying "Oh, we'd really love to come visit Canada, but we don't have a passport" can visit after all?
Is the passport, an airline (or commercial carrier) requirement only?