Several years after the destruction of the Oil Rig by the Chosen One, the NCR, convinced that the remaining Enclave forces were a threat to security of the region, sacked Camp Navarro. The NCR proved victorious, either capturing or destroying the base. The surviving Enclave forces scattered, hunted by both the NCR and the Brotherhood of Steel.
Remaining Enclave personnel in California either were recruited by the NCR, fled west and went into hiding, or fully integrate into the NCR by hiding their identity; those found out from time to time were arrested and tried for war crimes.Some were able to reach Nevada, where the NCR's more tenuous presence gave them the opportunity to quietly blend into large towns.
After sacking Navarro, the NCR recovered an item with the markings of the Divide's military installations, alongside lots more advanced technology they couldn't even begin to understand. This package was a detonator that contained missile launch codes that merely needed to get within range and activate the launch computers within a silo. When the Courier delivered this package to the Divide, the detonation signal activated the ICBMs below ground, causing the earthquakes and radioactive storms that shaped the Divide into what it is in the 2280s.
↑ 1.01.1The Courier: "Tell me more about the tribal." Marcus: "We were looking for a GECK to save the village of Arroyo. Eventually, we did. Nuked an oil rig in the process. We went separate ways after that. I went east into the Rockies, looking for other mutants like myself. Don't know what happened to my friend. I've got a feeling it turned out all right in the end." (Marcus' dialogue)
↑The Courier: "What happened to the Enclave oil rig and Navarro?" Judah Kreger: "Internal sabotage took down the oil rig - never did get the full story. The NCR took out Navarro, saying we posed a threat to the region." (Judah Kreger's dialogue)
↑The Courier: "What happened to Navarro?" Arcade Gannon: "After the Enclave's command structure fell apart, it was only a matter of time before Navarro was overrun by NCR forces. My mother and I left with some of the troopers from my father's old unit, the same people I've kept in contact with over the years. Anyone who didn't get out was killed by the NCR. Even some of the ones who escaped were eventually hunted down by the Brotherhood of Steel." (Arcade Gannon's dialogue)
↑The Courier: "I thought the Brotherhood were all wiped out at HELIOS One. How could they have survived?" Cassandra Moore: "After the battle, we consolidated our hold on the plant before pursuing our enemies. It was a mistake, to be sure, but there wasn't really any place for them to go. When we finally gave chase, however, they had simply vanished. Some of our people think they had some means of conveyance, like the Vertibirds the Enclave used, and hightailed it out of here. I think that they found someplace to hide close to HELIOS, and never went that far at all. Any other questions?" (Cassandra Moore's dialogue)
↑Fallout: New Vegas loading screen hints: "Though they were a powerful force in the west decades ago, the Enclave has not been seen or heard from in the Mojave Wasteland for years. Members who were not hunted down are believed to have traveled east - or successfully integrated into the NCR."
↑The Courier: "Where did the Enclave go?" Arcade Gannon: "A lot of different places. I only know what I was told. Some of them were cut down by the NCR and the Brotherhood. Some of them went east. My mother never told me what happened to my father, but she and I went south with some others and integrated into the NCR. When the NCR learned that Enclave personnel had integrated, we kept moving to the fringes. It's one of the reasons why I wound up out here." (Arcade Gannon's dialogue)