so i did a search on google and i got this, sorry if i don't know how to post a link but you can just copy and paste it.
is this the real site 4 or an already known base?
please add this to an existing discussion on Site Four such as the ATS mega-thread,
Site 4: More Secret Than Groom Lake?
Site Four is located within the boundaries of TTR, near the eastern border, about 10 miles east and slightly south of the TTR headquarters. Access to
Site Four is provided not only from within TTR, but also from a gate on TTR's eastern boundary. From this "Site Four Gate", as it is called, a high
quality dirt road (similar to Groom Lake Road) heads east and connects with Hwy. 375.
Site Four sits by itself on a large plain. It is easily observed from a number of locations, although from a distance. It is a large complex, spread
over several miles, with some of the buildings widely separated. It is also worth noting that while TTR is covered with an assortment of camera and
radar tracking facilities, there is a notable absence of these near Site Four, adding to its appearance of isolation.
Please visit the link provided for the complete story.