From the descriptions of the Pursuits related to Marin:
Now more machine than man, the Ninety-Niners continue to mindlessly excavate and hoard gulanite deep within the vault that is Mine 99.
Marin, like most of the Bay Area, is rich with gulanite. The Muir Union Mines once represented the best chance at prosperity for the people of Paradise.
Over time, the Ninety-Niners were consumed by a madness that compromised their humanity and fueled their lust for gulanite.
In their endless and insane quest for efficiency, the Ninety-Niners replaced most of their organic body parts with cybernetic enhancements.
”The price of true prosperity is a fee most people are not willing to pay. I mean, the Muir Union miners traded actual body parts for it! Regardless of that nonsense, at least those rust jobs understood sacrifice.”
— Varus Soleptor, CEO of Soleptor Enterprises
Marin was a miners’ paradise turned into hell. Crazed cyborgs have descended from the hiss to seize control of the roads and mining sites.