"J-Rod" Alien photo from Area 51, Nevada

Area 51 - Groom Lake, Nevada

In January 2006, space historian Dwayne A. Day published an article in online aerospace magazine The Space Review titled "Astronauts and Area 51: the Skylab Incident". The article was based on a memo written in 1974 to CIA director William Colby by an unknown CIA official. The memo reported that astronauts on board Skylab 4 had, as part of a larger program, inadvertently photographed a location of which the memo said:

There were specific instructions not to do this. was the only location which had such an instruction.

Although the name of the location was obscured, the context led Day to believe that the subject was Groom Lake. As Day noted:

In other words, the CIA considered no other spot on Earth to be as sensitive as Groom Lake.....

Area 51 Warning Signs

Area 51 Nevada, Satellite images

Area 51, Rachel Nevada

Area 51 ExtraTerrestrial Highway

A view from the Extraterrestrial Highway, Groom Lake Nevada Area 51

Area 51 ET - Extraterrestrials

Little AleInn - Near Area 51, Groom Lake, Nevada