Rob... Didn't mean to insult your intellegence, bro. From your post you sounded a bit surprised. In addition to tropo-scatter or tropo-ducting as it's sometimes called, FM signals also sometimes get transported by sporadic-e. This is a true skywave, where the signal bounces off the e-layer of the ionosphere, but is somewhat rare in FM and TV frequencies, whereas at lower frequencies this phenomenon occurs daily (or in the case of AM, nightly). I'd be interested to hear from some of you out there if you've experienced this phenomenon where FM signals may be heard 500 to over 1000 miles from the tower site. Here in Cleveland, I've logged reception from Moultrie, Ga. (900 mi.), Rapid City, SD (1200 mi.), and Gillette, Wy. (1350 mi.).