Here is what my lists from the Colorado Railroad Museum files: ``Denver and Rio Grande Western Railroad Company Seniority List of Engineers and Firemen, Alamosa Division Sub -Divisions 10, 11 & 12 January 1, 1920.''
I though the D&RG didn't become the D&RGW until 1924 but maybe that was the date when the railroad changed the classification system on steam locomotives. Herbert Danneman lists the change as 1922.
I have a Third Division timetable reprint dated March 28, 1920 so I would think the Fourth Division was still in place at that time.