Speaking of 'reaching up into Canada', I believe AM radio signals can be deflected off of clouds...I recall hearing stations from the deep south all the way up in cottage country in Ontario (2-3 hrs North of T.O.)...some kind of religious program. Surprised me how far AM can travel.
Hundreds of miles isn't a big deal for AM.
My mother lives about 350 miles away from AM720 WGN's 50,000 watt tower and she listens to them every day. At night, she sometimes listens to AM850 KOA (another 50,000 watt station) out of Denver - that's almost 800 miles away.
At night, AM radio waves are actually reflected off the ionosphere and can travel around the globe. This is how Shortwave radio works. Shortwave is the same technology as an AM, just at a different frequency. I've got an old little shortwave radio that I'll occasionally listen to. I've listened to broadcasts from Cuba, China, Japan, Germany, France, Russia, etc. With the internet, it's not quite as cool as it used to be, but it's still kind of fun.
