IDK, the Enclave has been kept pretty hush hush in Fallout 3 but with 100+ vaults across America I simply can't believe Black Isle didn't originally intend them to have remnants across the country. It was their vault; they funded the project for a specific purpose.
The Enclave's base was in the oil rig. They had started expanding to try to reinstate the US goverment, but all they had done by the time of Fallout 2 was set up several small outposts like Navarro, and scout old military bases for useful stuff. They had set the whole thing up ahead of time in preparation of the war, so why wouldn't they set up some system to monitor the Vaults from the base?
Also, according to the
Fallout Wiki :
[spoiler:9f9dc2e2a7]The real reason for the existence of these Vaults was to study pre-selected segments of the population to see how they react to the stresses of isolationism and how successfully they either re-colonize Earth or colonize another planet after the Vault opens.[/spoiler:9f9dc2e2a7]