Reilly's Rangers served in many ground and airborne missions in the Human-Covenant War. They were very skilled at their job, making every mission they had a success. They all had their own MOS, meaning each one did one certain task. They participated in the Fall of Reach, the Battle of New Mombassa, the escort of Master Chief to Installation 04, and miscellaneous other battles. Their HQ was based in Stananlaus, Mars and on Reach before it's fall. They disbanded 2559 after the crew they had either retired or died other than Sam and Regan, so they disbanded.