The next in line

The CIA soon decided they would need a new top-secret aircraft which could not only fly high, but fast as well. To help protect the security of this new project, on January 15, 1962 the government quadrupled the restricted airspace around the facility. Three months later, the A-12 made its first test flight at Area 51. For the next two years, the A-12 would remain hidden from anyone without special clearance. During the election year of 1964, President Lyndon B. Johnson wanted to unveil the A-12 to the American public. However, this was a larger task for the US government than they let on. President Johnson told the media that the A-12 was being tested at Edwards Air Force Base in California, but actually, the plane was being tested at Area 51, the base that the government denied existed. When the press was invited to view the planes at Edwards, the aircraft had to be relocated quickly to the base, and when they arrived they were hastily ushered into waiting hangars to conceal them from view. Unfortunately, this was done so quickly that the planes were still hot from aerodynamic heat. This intense heat caused the sprinkler systems to activate, showering all the press waiting to view the plane for the first time.

Courtesy of Wikipedia

Although the A-12 was amazingly futuristic for its time, this did not stop the government from immediately beginning work on its successor — the SR-71 Blackbird. Along with development of the Blackbird, the base at Area 51 was expanded to include the addition of new hangars and fuel tanks. It was during this same time that the history of Area 51 veered away from a course of historical fact and into the grey area of speculation. All designations of Area 51 or Groom Lake were left off government maps, and government satellite images of the location were no longer collected. That meant that Area 51 was now so secret that even someone with the highest clearance in the government was not allowed to look at it.