Doug,
Not sure if it'll help with what you're looking for, but just to let you know. The Roam & Pool TGs for VIPER should be SYSTEM wide, such as:
East Roam/Pool TGs will transmit on all sites in the C508 system.
Central Roam/Pool TGs will transmit on all sites in the 6038 system.
Piedmont Roam/Pool TGs will transmit on all sites in the C123 system. and
West Roam/Pool TGs will transmit on all sites in the C92D system
This is regardless of affiliations and who's listening on what site.
There is also statewide calling, fire, ems, law, and general government.
The SMAT TG is also statewide (11504 I think)
Each SHP Troop has a troop wide talkgroup... I'm not sure if the mutual aid TG is active on all sites in the troop though. SHP Also has 4 statewide TGs.
I'm not sure about the 3 LZ Coordination TGs and what permissions they have. They could be regional, or only on sites that radios are affiliated to.
I don't believe the DPRR TGs have a large coverage area. I've been listening to the Transylvania TG one time and only heard them on one of the four local towers I monitor.
Look under the "Systemwide/Statewide" heading in the VIPER database, and also do a search (Ctrl + F) for "statewide" & "S/W" and that should help narrow down a lot of the major TGs you're looking for.
I hope this helps, and if it doesn't apply to your question and I misread it, disregard