Tom
You most likely have the latest map update from Garmin in your unit. The latest is Navigator North American 2011.20. Now the Garmin web page leaves a little to be desired in getting around but here are a couple of links that will give you an idea as to what areas are covered.
I hope this works. The first link is drilled down to an area of TV that will show you what is covered in the latest addition. As you can see most of the new area of TV is not included. It usually takes 6 to 9 months for NAVTEQ to get their vans into the area to get the readings and update the database.
http://www8.garmin.com/cgi-bin/mapge...&rz=0&k=1&sc=1
In cast that did not work try this link and you will have to drill down and move the map around to get to TV area. I wish they had a drag feature and use the mouse to zoom in as that would make things a lot easier.
https://buy.garmin.com/shop/shop.do?...56#coverageTab
You may have to cut an past the links into another tab or window to get them to work.
The life time update is available from Garmin for $89.95.