On September 19, 1957, the United States detonated a 1.7 kiloton nuclear weapon in an underground tunnel at the Nevada Test Site (NTS), a 1,375 square mile research center located 65 miles north of Las Vegas. This first-ever underground test was part of a series of 29 nuclear weapons and nuclear weapons safety tests conducted at the NTS between May 28, 1957, and October 7, 1957. At the time, the U.S. and the Soviet Union were engaged in a Cold War and a nuclear weapons arms race. In the 1996,the United States signed a Test Ban Treaty.
