I live in a town that is the "Roller Coaster Capital of the World", on the south shore of Lake Erie. Not far from Canada. I have always found Canadian coins in circulation. The giant amusement park used to accept Canadian at par.
40 years ago I was a bartender at a bar near the freighter docks. Those Canucks would come in off the boats and spend money like crazy. We charged 10% exchange fee. They made of our US paper money, because it was all one color.