Ross:
A few Marshall pass train register pages from the 1920s survived and I have heard of a few misc pages here and there. Some Gunnison pages from the late 1940s also survived.
Fred Vernon, who was the last D&RGW agent at Antonito was agent at Crested Butte during WWII. He told me that the D&RGW HQ in Denver sent a message to all the agents telling them to pack up all old papers and ship them to Denver for the WWII scrap paper drives. He said he filled two narrow gauge box cars with papers from the Crested Butte depot.
I am writing a book on D&RGW/RGS snow fighting operations and the lack of these papers has made the research very difficult as I have had to rely on newspapers which were not always accurate or complete.
If all of the train register books had survived, someone could write a fantastic history of the railroad.