National security scholars at George Washington University have some good news and bad news for UFO buffs - the U.S. government has finally confirmed the existence of Area 51 in Nevada, but it makes no mention of little green men or alien spaceships.
The government acknowledged the existence of the mysterious aviation test site known as Area 51, a remote installation about 80 miles (130 km) northwest of Las Vegas, in a newly declassified CIA history of its U-2 spy plane program.
After decades of extreme secrecy surrounding the site, stoking conspiracy theories about UFOs and experiments on alien spacecraft, the CIA lifted its veil on Area 51 in response to a public records request from George Washington University scholars in Washington, D.C.
Publicly released online on Thursday by the university's National Security Archive, the 400-page CIA history contains the first deliberate official references to Area 51, also known as Groom Lake, as a site developed by the intelligence agency in the 1950s to test fly the high-altitude U-2 reconnaissance plane.
Other top-secret aircraft were tested there later, including the supersonic reconnaissance A-12 aircraft, code-named OXCART, and the F-117 stealth ground-attack jet, said archive senior fellow Jeffrey Richelson, who asked for the CIA's U-2 history in 2005.
A newly revised document restoring numerous references to Area 51 that had been redacted in earlier versions was furnished by the CIA a few weeks ago, he said.
"It's the first time that there must have been a senior-level decision to acknowledge the term 'Area 51' and its specific location," he told Reuters on Friday.
Chapter 2 of the CIA history recounts how Richard Bissell, the CIA officer then overseeing development of the U-2 plane by Lockheed, first spotted the site on an aerial scouting mission over Nevada in April 1955, accompanied by an Air Force officer and two others.
The four men landed their plane near an old, abandoned air strip at the edge of a salt flat known as Groom Lake near the northeastern corner of the Nevada Test Site, the nuclear proving ground then controlled by the Atomic Energy Commission.
The group agreed that Groom Lake would "make an ideal site for testing the U-2 and training its pilots." Bissell subsequently asked the Atomic Energy Commission to add the area to its Nevada real estate holdings, the account says.
"AEC Chairman Admiral Lewis Strauss readily agreed, and President Eisenhower also approved the addition of this strip of wasteland, known by its map designation as Area 51, to the Nevada Test Site," the document says.
To make the barren new facility seem more appealing to its workers, managers of the U-2 program dubbed the facility "Paradise Ranch," which was later shortened to "the Ranch."
Photos of the site and a newly declassified map outlining and labeling the location were also included in the document.
Richelson said he could recall at least two previous government documents in which an incidental reference to Area 51 appeared, but he assumed those were inadvertent because they were devoid of any other details or context.
The multiple detailed references to Area 51 in the latest CIA account - the document's index lists at least 12 mentions - show that they were deliberate, he said.
The intelligence agency had little to say about the disclosure.
"What readers of the CIA study will find is that CIA tests its U-2 and A-12 reconnaissance aircraft at the site in Nevada sometimes referred to as 'Area 51,'" CIA spokesman Edward Price said. "What readers won't find are any references to aliens or other conspiracy theories best left to the realm of science fiction."
Among the more sensational pieces of UFO conspiracy lore linked to Area 51 is that the remains of a flying saucer that supposedly crashed near Roswell, New Mexico, in 1947, were brought to the site for reverse engineering experiments that attempted to replicate the extraterrestrial spacecraft.
 Richelson said the CIA document makes no mention of any such theories. But he pointed to one passage that discusses the relationship between U-2s and unidentified flying objects "in the sense that people sighted U-2s in a time that they were very secretive and at very high altitude and didn't know what they were, and in that sense they were UFOs."