First alleged sighting of UFOs: June 1947, in Central Washington State. Kenneth A. Arnold, an American aviator and businessman, claimed to have seen nine unusual objects flying in a chain near Mount Rainier, Washington.
Famous UFO crash site: Roswell, New Mexico (December 1947). Authorities in Roswell claimed having found the proof of alien life. When they later retracted their story, Jesse Marcel, the original military investigator, declared that there was a government-ordered cover-up and pointed at the top-secret Area 51.