Though government officials denied its existence for several decades, the CIA has confirmed in recently released documents that Area 51 is real.
While it doesn't make any references to conspiracy theories and paranormal activity reports typically associated with the plot near the Mojave Desert, the CIA acknowledges its existence several times in newly declassified documents on the history of the U-2 and OXCART spy plane programs. The documents were obtained by George Washington University's National Security Archive through a public records request.
The more than 400-page history describes how Area 51 was used as the base for the spy planes, which conducted surveillance around the world following World War II, particularly in the Soviet Union during the Cold War.
Jeffrey Richelson, National Security Archive senior fellow, read through the history in 2002, but all mentions of Area 51 had been redacted, USA Today reported.
Richelson made another request in 2005, which the agency responded to a few weeks ago with a significantly less redacted version. Richelson told USA Today this may be a sign the CIA is becoming less secretive about Area 51 and what goes on within its borders.
The history is also significant in that it releases other previously classified information, such as the names of pilots, code names, locations and funding arrangements associated with the U-2 program.
The report states that then-President Dwight Eisenhower wanted pilots flying the U-2 planes to be non-U.S. citizens to protect confidentiality of the operations.
"It was his belief that, should a U-2 come down in hostile territory, it would be much easier for the United States to deny any responsibility for the activity if the pilot was not an American," the report says.
Though Area 51 is not the government's best kept secret (it has been referenced in other government documents and shows up in books on aerial surveillance) these documents are the first that acknowledge its existence and given specifics about its operations, CNN reported.
But the documents do give some explanation to reports of UFOs in the area after the government began testing the U-2 planes.
The military began testing the planes at high altitudes in able to conduct reconnaissance missions over the Soviet Union, with the belief that radars would not be able to detect aircraft flying above 65,000 feet. Most planes at the time flew at altitudes between 10,000 and 20,000 feet, and even military aircraft flew below 40,000 feet.
"High-altitude testing of the U-2 soon led to an unexpected side effect – a tremendous increase in the reports of unidentified flying objects," the report says. "At this time, no one believed manned flight was possible above 60,000 feet, so no one expected to see an object so high in the sky."
These reports, both from air traffic controllers and people on the ground, led to the Air Force's Operation Blue Book, in which officials attempted to explain the sightings by linking them to natural phenomena. Air Force officials also checked reported UFO sightings against U-2 flight logs.
"U-2 and later OXCART flights accounted for more than one-half of all UFO reports during the late 1950s and most of the 1960s," the report says.