... as the USA feverishly worked to build huge stockpiles of atomic weapons the need to find and mine Uranium ore skyrocketed. Modern day prospectors set out for 'them thar hills!' in a 'uranium rush'. Deposits of the mildly radioactive ore ( it had to be refined many times for bomb production) were plentiful in North America. Less so in the Soviet Union.
all images- Right click- open in New Window= super colossal size!