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.

The complex seems of indistinct purpose. There are a number of towers containing various antenna, including steerable microwave dishes, but there are also some towers devoid of antennas. However it does not have the appearance of a Radar Cross Section facility. There are a number of earthen covered bunkers, indicating storage of either explosives or other dangerous materials. What appears to be a main headquarters building was observed, a large two story office type structure. Surrounding it were a number of other industrial style buildings. No airstrip was observed, but other maps indicate the presence of a heliport.

Little is publicly known of Site Four's mission or purpose. It seldom even shows up on maps of TTR, in spite of its size. There is a rumor that secret solar energy research is conducted there. However, visual observation of the facility reveals nothing even remotely in the way of solar collection apparatus.

Discussions with a former TTR worker revealed a few interesting pieces of information. The workers at TTR's main complex considered Site Four even "more secret" than the main complex. People bound for Site Four had to pass through another gate within TTR before gaining access to Site Four. And oddly, while workers at the main TTR complex were allowed (and perhaps even encouraged) to live in one of the nearby local communities, this was not the case for Site Four employees. They were required to utilize the commuter flights from Las Vegas.

Update:

A recently released environmental impact report for TTR (1994 Site Environmental Report, TTR), contains a few new clues. While not mentioning Site Four anywhere in the document, it does identify a facility that would be immediately adjacent to where Site Four has been shown on earlier maps. It could account for some of the facilities seen and noted above.

This facilty is labeled as the "554th Range Squadron O&M Complex". According to the index of abbreviations in the EIR, "O&M" stands for "Operations and Maintenance". What is operated and maintained there is not clear. The location shown for the 554th O&M complex is about 2 miles west of where other maps have indicated Site Four to be.