Groom Lake just deals with it (the tourists). They have the routine down. The place may be famous, but you have to be on Tikaboo to see anything. But
if you are on Tikaboo, they know you are there. Maybe they care, and maybe they don't. It depends on the tests. If you google N105TB, you can see
video shot from Tikaboo of N105TB analyzing (following in flight and "sniffing") a Sukoi-27. I've photographed that SU-27 flying east of the ET
Highway during a Red Flag. They knew with 100% accuracy I had a camera and was going to photograph it.
If there is something they don't want you to see, they test it on moonless nights.
In the internet age, if the US started another base, just how long do you think it would remain a secret? Case is point is that "Mystery at Salt
Flat" website that popped up a few years ago. Hey, moving your CIA training base to some hell hole in Texas seemed like a good plan to me. However
the website author quickly found the CIA CN235 leased to Devon.
Mystery at Salt Flat
The USAF just can't be moving all this infrastructure anytime they think their secret base has been discovered. Rather, they have countermeasures,
and until we have satellites with Xray vision, there are no counter-countermeasures. When the EMCCD cameras reach consumer prices, the base will
probably have an issue with the tourists camped out there at night.
Back to the link, I like the animated gif of Papoose Mountain. It screams "nothing to see here!"
Regarding the so called tunnel entrances, it seems to me this type of entrance would be a problem when it rains. Of course there could be some
mitigation scheme not visible on the satellite image. And only one of the "entrances" appears to have an opening. I suspect the ramps have something
to do with the landfill, and if someone were an expert in such things, they would explain the function.
Often things look way more interesting when your imagination runs wild, but are quite boring when you know the details. For instance at
there is a structure that people believed was a tunnel entrance. Actually they tune up the aircraft gun by firing at that structure with the plane
parked on one of the nearby circles.
Look at the jet deflectors at Palmdale.
34°38'34.79"N 118° 4'56.13"W
If you use the time machine, you can see that sometimes they have covers where the aircraft is parked, and sometimes they don't. When covered, it is
probably a secret aircraft. I suppose there is a chance the plane would be revealed when moved, but they could just put a tarp over it and tow it to
the test stand.