Doug:
The primay narrow gauge traffic from Salida to Pueblo was coal and coke from Crested Butte to the CF&I steel mill. The mudhens were the primary power on Marshall Pass and the Crested Butte branch due to the heavy coal traffic. The D&RG had a number of standard gauge locomotive and cabooses equipped with dual gauge couplers for use on this line.
A 1910 D&RG report to the BOD stated that the cost of maintaining all the dual gauge switches was prohibitive and as the standard gauge rail was getting heavier and heavier, the BOD was asked to fund removal of the dual gauge and establishment of transfer facilities at Salida. When the USRA took over the railroads in WWI, building of transfer facilities was put on hold and the coal was transferred manually by shovel gangs unitl the barrel was built in 1924. As soon as the barrel was complete and its operation confirmed, the D&RG removed the third rail from Salida to Leadville. The last narrow gauge line in the Leadville was the Ibex branch and it was standard gauged in 1917. After 1917, the D&RG had no narrow gauge power in Leadville and switched C&S narrow gague cars with standard gauge engines equipped with dual gauge couplers. The standard gauge 2-8-0 at the Colorado RR Museum was so equipped.