Yeah, that's what I thought. Although I did know there's a great deal of controversy over how far east if goes, and people laugh at New Yorkers for thinking of Cleveland as basically the same as Kansas.

In Canada, the Prairies go from the Rockies to the Shield region where things get stony and boggy. And extend north until it's too forested for the descriptor to apply, maybe a quarter of the way to the Arctic coast on average (so it's mostly taiga nd tundra with just a little bit of farmable area).