The Moffat Line was originally constructed by the Denver, Northwest & Pacific, later renamed to the Denver & Salt Lake (D&SL). Never healthy financially, in 1936 the D&SL was put into joint receivership with the D&RGW. From that time on, the Rio Grande became an increasing presence on the Moffat line, until 1946 when the two railroads were officially merged.
My layout’s D&RGW era actually consists of several mini-eras. Currently I can do the
early and late 1960s, the mid-1970s, early 1980’s, late 1980’s. Essentially, I select a year and choose rolling stock and power to suit. (I also change out any vehicles on the layout to match the era.)
(For reference, here is the track plan.)