Atlas Obscura
MK Tunnels in Orangeville, Utah
By 1950 what was to become known as the Cold War was settling into place. The Soviet Union had detonated a nuclear device in the late 1940s, so the US nuclear monopoly was broken. In addition, both sides would successfully test thermonuclear weapons (a.k.a. hydrogen bombs) in the early 1950s. So the sheer destructive power of nuclear weapons, even before operational thermonuclear devices, motiv…
horizontal tunnels dug in Navajo Sandstone for nuclear tests