1 Jamie: How the heck did we end up in Montana?
2 Adam: I dunno! I booked tickets to Glasgow International Airport.
3 Man: Yah, you betcha. Glasgow International Airport, Montana. Where I picked you up.
4 Adam: Who in their right mind would put an international airport in Montana??!
4 Man: It's a long walk to Canada...

There is indeed a Glasgow International Airport near Glasgow, Montana. Thanks to the reader who pointed this out back when Adam and Jamie first discussed going to Glasgow on their way to Loch Ness.

Apparently Glasgow International Airport currently only operates flights to and from Billings, Montana. Which isn't exactly international, so I'm not sure why it gets such a high falutin' moniker. It used to be a US Air Force base, so I suppose they might have flown planes to other countries back then.