add county layer to map

How could I add a kmz file layer to a map created with ProMaps for Google to show county boundaries and names?

I'm not sure how you'd add a kmz file layer to the map, but the map will already show the country name and borders automatically. Is there a specific reason you would need it to show more information?

No reason a kmz layer is absolutely necessary if there's a built-in way to show county labels (at most zoom levels). My map does not currently display counties or their names. Where in the ProMaps code can I activate that option?

You shouldn't actually have to enable it. It should already be showing if there is a country border showing. Do you have a url to a page where I can see your map?

This is the a temporary url for a non-login version of the map page -

eagleDataCopy.php

The points on the map are queried by county, so the distribution of points gives a rough idea of the county pictured, but there are no county names nor borders at any zoom level.

I really appreciate the help you might be able to offer.

Ah, I'm sorry, I misread the county as country, not county. You are right, the county lines are not mapped out on the map.

Unfortunately I don't have any experience with kmz or kml file, but someone posted up some sample code on how they got this running:
google-maps-api-using-kml-files-from-my-maps/

There may also be other users on the forum that have experience with using these files that may be able to help you.