Thanks for your message Bernie.
I do recall reading in the Poor book on the line rising above the Loop. I do not know a great deal about this area or any but I remember that as it was being discussed the issue of the grades being made above the loop, the station building was being prepared in Denver for the town above. I should remember what that town was but can not off hand. Silverton? I don`t really know. But I do remember reading that, in the memorial addition.
Regarding the whistles and going out on a limb here, did some engineers have their own whistles that they could signal to towns ahead with?
John