Free-fire area OZONE
During the Battle for Earth, from November 10 to December 3, 2552, Covenant forces excavated and occupied built-up positions at this location. On November 19, the UNSC deployed nuclear weapons against multiple shielded enemy positions at OZONE. Two weeks later, Fleet Admiral Joseph Harper directed Operation: MARSH FLASH, which successfully eliminated clusters of high-value Jiralhanae attempting to activate an artifact in this area.
- OZONE's coordinates are listed in the Halo Legendary Crate as (31.565043, -110.343567), which roughly places it in present-day Fort Huachuca in southeastern Arizona, about 187 miles from New Phoenix.