GAZ has about 600k entries representing different geographic entities, from the Mariannas Trench to Minnesota.
Efforts on GAZ have restarted after a period of hiatus. Lynn Schriml has been assigned contact for GAZ. A group of us are attempting to work through various issues on the tracker, including figuring out a better way to manage GAZ in GitHub, linking GAZ to ENVO, and integrating GAZ with Wikidata (and from there, other resources like Geonames).
You can follow the tracker here:
Like any OBO ontology, anyone is welcome to post issues or follow the tracker.
We also have a mailing list, where amongst other things you will find announcements of regular meetings:
Anyone can sign up, but as with any google group, include a brief message when you sign up, especially if you are using a non-academic email address, so it doesn't look like spam.