" The Operation Hardtack II nuclear test series would prove even bigger than Plumbbob, in terms of the number of tests. From September 12 to October 30, 1958, an astonishing thirty-seven nuclear bombs were exploded—from tops of tall towers, in tunnels and shafts, on the surface of the earth, and hanging from balloons. Areas 3, 5, 7, 8, 9, 12, and 15 served as ground zero for the detonations, all within eighteen miles of Area 51. "

― Annie Jacobsen , Area 51: An Uncensored History of America's Top Secret Military Base