Well now I am confused. Oil Rig went Boom killing most of the Enclave. A computer in DC starts working and tells what's left to go East. Some stay behind at Navarro which later falls to NCR. From what I got from Arcade was that many went all over the place to get away from NCR and start a new life much like the remnants in New Vegas. They no longer wanted to be apart of the Enclave but NCR and BoS were hunting them so they had to split up. Only the die hards I guess went East. So in the end FO3 had way to many Enclave. I don't recall Enclave having citizens as in people not in the Enclave but under their protection. Maybe a few Enclave scientist holdouts in a bunker in Chicago but thats not enought to say Enclave have a real presence there.
We don't know when the Outpost was built but the Midwestern BoS have been there since before the time of FO2 so its possible they did find the outpost.
Actually reviewing what Arcade says, maybe it isn't as clear cut, I don't know, here's a good link to a For Auld Lang Syne walkthrough were the actual dialouge isn't skipped past by pricks who care nothing for lore.
http://www.youtube.com/watch?v=SXWUd9-8Nvo
"Where did the Enclave go?"
"A lot of different places. I only know what I was told. Some of them were cut down by the NCR and Brotherhood of Steel. Some went East."
Now I always took the fact that he was told by his folks they went lots of places to mean that the Enclave split up before Navarro was captured and that's how the parents know they went losts of places, otherwise they would have just told him some went east and the rest scattered.
I refer to
everyone in the Enclave as citizens because that's what they are, they are citizens of the United States of America, Bethseda could have done to remember that before turning the Enclave into solely the US Army but... The people at Navarro only left because the NCR attacked, aside from the odd deserter it stayed operational for years after the destruction of Navarro and some people on the East Coast clearly still thought it was operational as that's were ED-E was origionally headed. And yes Fallout 3 had
WAY to many Enclave unless there was some strict, forced pro-creation programme for the 30 years between FO2 & FO3. Personally I consider the base still operational in the manner described earlier, repairs were made to ED-E in at least the state of Illinois sometime in the last 3/4 years since 2277/78. I personally condiser that proof enough the outpost was still manned and operational till at least 2278, depending on ED-E's speed, and I see know reason why in those particular years they should be found and destroyed. I know some people are sick of the Enclave after FO3 turned them into soft, squishy, cliche, stock cannon-fodder but god-damnit that's the point, Broken Steel
CANNOT be the end of the Enclave as a organisation.