Considering the secrecy and security levels for Groom Lake/Area 51...and knowing its background....one must wonder why it continues yet today.
There must be some very sensitive programs going on there for sure.
Not far from my current abode there is a small government facility.....where booms and bangs are frequently heard....and in the past small groups of very hard men trained there for a take down of a rather high value target in an unfriendly friendly country not our own.
Lots of secret locations to be considered.
It is good I suppose that the general public do not know everything that is going on at most of those places.