The first time I heard it they were talking about a site just west of Winslow, Arizona but the conversation drifted to other locations, most of which I was unfamiliar with because they were talking in railroad lingo which describes stretches and geographical features instead of towns. They were railroaders as had been their fathers. From what they said it was general policy and a perusal of old news stories should pinpoint some locations. I brought this story up once elsewhere and was told that there were several major sites in Nevada.
I wonder what was in the other cars that they pushed in. Didn't think to ask.