Bunker 99 was part of a former United States Army facility established during the early stages of colonization of Paradise Island. After the United States government collapsed in 2085, the base, its personnel and equipment remained solely independent for four years until the Mirage Corporation had absorbed them into its paramilitary arm Mirage Security. Prior to May 19th, 2138, the Mirage Corporation would pull away its forces from the base, abandoning it and allowing it to fall into the hands of smugglers, who utilized the base as a hub for distributing contraband.
Bunker 99 is the setting of Prologue: Nakata, the first mission in the Futuristic Zombies campaign, where it is controlled by the Private Army.