It looks like the Weapons Storage Area (WSA). Most former SAC and TAC bases had them built during the cold war. They were used to store the nuclear
warheads that were not on alert. Very secure areas, and not recommended to go into unless one wants to eat the pavement for an hour while the SPs try
to figure out what one is doing there.
I am just stating what it looks like to me. It does look like the WSF, and I have seen many of those in my military career. The OP was asking us what
we thought, and I gave my opinion. I could be wrong, but it does not look very mysterious to me.
Sorry to take so lond to reply i've been a little busy.
I was an "escort" for lack of a clearer term.
I still have a clearance I have to keep, so I do apologize for being a bit bland with my answers. I'll see if I can come up with a few things for ya
though.
Might take me a little bit as I am traveling between continents the next few months.
You guys are pretty on the spot with some of the things you mention though.