How high are the towers? The obstacle database doesn't include anything below ~300' AGL. It's also rather unreliable. There was a 500' tower in our area that was removed several years ago, and it still gets very excited when I fly over the spot where it used to be. There is another that triggers a warning that was lowered to about 100' years ago. I would never, ever depend on the Garmin database alone to protect me.