In 1962, the Atchison, Topeka, and Santa Fe Railway began planning a new railway between Needles and Barstow through the Bristol mountains in California. The straighter, more level route would be 15 miles shorter than the old line, shaving 50 minutes off the trip. But getting through the mountains would require either drilling a tunnel or excavating a new pass; the railway judged the cost of doing either with conventional means to be prohibitive. So, in December of 1962, the Santa Fe Railway contacted the US Atomic Energy Commission (AEC), to ask if the job could instead be done with hydrogen bombs.
That inquiry was just what the AEC had been waiting for.[Ki]