Anon can offer some additional circumstantial evidence that there could may be a tunnel system at/near Zorro ranch:
A nearby ranch has multiple billions in proven precious minerals, but has been unlawfully prevented from mining for decades. This ranch actually has the oldest mine in north America (native american turquoise mine), and is a touristy place now. No sauce, anon is just in the loop.
Anon is suspicious that the mining was stopped to preserve underground tunnels.