What is this very isolated, modern aviation/heliport in Northwest Antelope Valley, California? There's a modern facility at 118 53' 16" 34 9' 28" or about 9 miles north of Neenach, California. It has 5 hangars - 1 very large, 1 medium, 3 small - with other large buildings and a large water tank (a million gallons?). It sits in the foothills of the south side of the Tehachapi Mountains. The only land access is a meager dirt road, almost a 2 track.

Any suggestions as to what it is?
It appears to be the Northrop Tejon Ranch RCS facility. It is used for testing of radar cross sections. There’s a page here with a little more info on it.