The Central Intelligence Agency publicly acknowledged the existence of the base for the first time on June 25, 2013, following a Freedom of Information Act request filed in 2005. The CIA also published declassified documents concerning the history of the U-2 and A-12 OXCART aerial surveillance programs that were constructed and tested at Area 51. The documents claim the site's secret status was a way to keep information from the Soviets, rather than to cover-up an alien encounter.

One theory proposes the existence of a disappearing airstrip nicknamed the "Cheshire Airstrip", after Lewis Carroll's Cheshire cat, which briefly appears when water is sprayed onto its camouflaged asphalt.

Like the Groom Lake facility, the Tonopah Test Range, located about 70 miles (110 km) northwest of Area 51, is a site of interest to conspiracy theorists, mostly for its use of experimental and classified aircraft.

More than 2,000,000 people responded to the anonymously posted event, which was scheduled for September 20, 2019, and billed as "Storm Area 51, They Can't Stop All of Us." Between 1,500 and 3,000 people actually showed up in rural Nevada, and approximately 200 people approached the gates of Area 51 for the "raid" on the facility. According to the Lincoln County Sheriff, two people were arrested at the event, and the rest were dispersed by authorities.