Mon Pays was #30. American Woman was #5. Northwest Passage was #4. I too find Northwest Passage very moving, despite the bathos of the song turning out to be about a guy on a car trip (en route to the Vancouver Folk Festival, presumably). I think the "one warm line" is the vanishing thermal trace of a solitary warm-blooded explorer traversing a frozen landscape. It refers to the ephemeral human presence in the wilderness which IMO is the true essence and symbol of Canada--not some crummy highway or railroad.