Geography question

Someone asked me the other day, "How many states lie at least partially north of the southernmost point of Canada?"

I thought of Ontario dipping down the way it does, counted the border states, and replied, "Ten." (I forgot the panhandle of Idaho.)

What's your answer?

(Scroll down for the correct answer.)

The correct answer is 27. The US-Canadian border goes through the middle of Lake Erie, and there is a tiny island called Middle Island which lies just north of that border. There are 27 states, including California, which include area at a higher latitude than Middle Island.

(You can probably stump others with this just as you and I were stumped.)