I hope that I can ruin your day by getting you to read this map (courtesy wikipedia) of US town names that are portmanteaus of the two (or sometimes more) states they are near the borders of
@regehr Do any other countries do this?
List of geographic portmanteaus - Wikipedia

@regehr @14mission

The border portmanteaus section is virtually entirely the US though

@gbargoud The US is kind of unique for having mapped out states first and building towns later. And we have a lot of arbitrary compas-grid borders that make border-spanning towns more likely (instead of rivers or mountain ranges).