530-B HARKLE ROAD, STE 100, Santa Fe, NM, 87505, USA
Meshtastic LLC is registered in Sante Fe, New Mexico, USA. That information is not contained in the meshtastic website.
The head office address given is that of a registration agent though: New Mexico Registered Agent by High Desert Corporate Filings LLC
Meshtastic® is a registered trademark of Meshtastic LLC
Meshtastic trademark owned/controlled by Meshtastic LLC. US based I presume (given that examples I saw on the site take USA as default location).
Meshtastic LLC (and Meshtastic Solutions LLC, a service provider on top of the network it seems) are USA, New Mexico registered corporate limited liability entities.