The Rio Grande Southern used the D&RG(W) Operating Department Rule Book to govern their operations from the 1896 Receivership through the end of the road, even though they were independently owned and operated after 1929.
In January, 1938, the D&RGW did a major rewrite of their Rule Book. It was at this time that the side and front lenses on the rear markers were changed to yellow. It is believed they were green prior to that but I have yet to see a post 1891 to 1938 Rule Book to verify that. Green is assumed. To quote from the RGS Bulletin Book:
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Bulletin Number 20
Durango, Colorado, July 14, 1939
C.H. Rhodes, Foreman, E.D. Randow, Ridgway, H.M. Grays, Durango,
Bulletin Boards, All Agents, All Section Foremen:
Effective at once we will observe D&RGW Book of Rules dated
January 1, 1938. We will use our present Form 19 train orders for
all purposes until supply used up and will equip cabooses and
engines with proper color markers as soon as possible.
O.B. Olson, Superintendent of Transportation and Trainmaster.
__________
As I mentioned, there is a copy of a 1891 Rule Book available on DRGW.net and it is interesting what is said under the section entitled "Markers" in Rules 33 and 34:
"33. Each train, while running, must display two green flags by day and two green lights by night, one on either side on the rear of the train, as markers, to indicate the rear of the train.
Freight trains will display an additional green light in the cupola. Yard engines will not display markers. [emphasis added]
"When attached to mixed or freight trains engines shall display, from top of cab, a green light toward the rear."
Now, having established that the train will display green lights at the rear, Rule 34 goes on to say:
"34. Each train running after sunset, or when obscured by fog or other cause, must display the headlight in front, and two red lights in the rear.
Freight trains will display an additional red light in the cupola. Yard engines must display two green lights instead of red, except when provided with a headlight on both front and rear." [emphasis added]
Confused yet? Green at night. Red after sunset. Lots of head scratching must have occurred!
