Black projects
Courtesy of Wikipedia
In 1968, everything pertaining to Area 51 was newly categorized as a "Black Project." This meant that everything inside, underneath or over the base was considered a top-secret project. It was not easy or cheap to orchestrate such large projects while keeping them quiet. For this reason, the government implemented the "Black Budget", which was a secret pool of taxpayers' dollars. Because of its secrecy, this money was largely uncontrolled. Area 51 researchers estimate that $30 billion dollars per year was spent from this budget, with only one-third being spent on the actual projects. The other two-thirds was said to be spent trying to keep the projects secret. This included background checks on employees, transportation, security and possibly even surveillance of the employees that worked there.
It may seem as though the employees at Area 51 may have had a better idea than the general public about what was really going on inside the facility; however, even employees were kept in the dark. If a plane from one project was rolled outside of its hangar, the employees from every other project were required to retreat into their project's hangar to prevent any one employee from gaining additional information. All employees were required to sign strict confidentiality contracts and many families had no idea what their family members were doing during the workweek.
Courtesy of Wikipedia
Throughout most of the 1970s and 80s, operations at Area 51 took place without much public interaction or knowledge of what was actually occurring at the facility. Rather than supplying disinformation, as the government had been doing for so many years, they now took the approach of keeping quiet and denying all accusations regarding the activities at the base or the existence of the base itself. The people who did know of Area 51 would usually fall into one of two categories: the aviation buffs who believed that the government was testing the limits of aircraft technology, and UFO enthusiasts who believed that Area 51 was the site for storage and testing of alien spacecraft.