I just downloaded the US States and Counties.
It came up fine on my computer in the Garmin program.
The maps show the county boundries but no roads.
How do I "overlay" this onto my Mapsource maps?
Thanks
You can't overlay it over the MapSource map; it will display over the maps in the GPS unit but MapSource doesn't have the ability to display two maps at once.
This is a limit of the software.