With Area 51's overdue military declassification, those who used to work there are finally free to speak about the projects they developed. All those UFO rumours, it turns out, have a pretty reasonable explanation.
The men at Area 51, among other projects, worked on the OXCART spyplane, now known as the SR-71 Blackbird. The mach-3 plane was unlike anything ever seen before, designed to spy on the Russians during the Cold War, and so it kind of makes sense that such odd flying objects were seen around Roswell back in the day.
The stories the Area 51 workers have are almost as crazy as UFOs, however. For example: During the first flight of the OXCART, the plane malfunctioned and the pilot ejected into a field, where three civilian passersby in a pickup truck stopped to help him. The pilot warned the men not to go near the top-secret plane, saying there was a nuclear weapon on board as a deterrent. The men, spooked, dropped him off at a police station where the CIA picked him up.
"As for the guys who picked him up, they were tracked down and told to sign national security nondisclosures. As part of [the pilot's]own debriefing, the CIA asked the decorated pilot to take truth serum. "They wanted to see if there was anything I'd forgotten about the events leading up to the crash.""
The agents listed the crashed plane as a generic Air Force plane, and it's still listed that way in the records today.