Denver & Rio Grande Western F-7 #5654 at Denver Union Station, Denver, Colorado, August 20, 1964, photo by Chuck Zeiler. According to http://www.drgw.net/info/index.php?n=Main.F7
, it was completed June 1950 (c/n 11406 on EMD order #6093), retired from the RIo Grande in May 1970, to Alaska RR 1530 May-1970, wrecked 1975, rebuilt 1976 retired ARR 1986, to MDT Scrapped 1990
Many moons ago, I contributed this photo to a book by Joseph A. Strapac entitled, "Rio Grande Diesels, A Pictorial History, Vol. 1", and in it he captioned the photo thusly:
"Rio Grande passenger trains #3 and #4 were in actuality a contract service for the Missouri Pacific so that its 'Colorado Eagle' train could reach Denver, rather than terminate with the MP freigt trains in Pueblo, Colorado. Ready for its afternoon departure to St. Louis, the seven car train will go out on August 20, 1964 behind D&RGW #5654 and Texas & Pacific's 1951-vintage E-8 #33. Last gasp for this service was to come in May of 1966."
I would suppose there is a good reason why the Rio Grande unit had to lead. Perhaps the extra 1500 horsepower helped across the rolling terrain between Denver and Pueblo. I'm aware of the Chicago & North Western's insistence on a C&NW unit leading on all trains on their system; it was to trip the signals with an induction coil generally located on the front truck of all C&NW road locomotives in this era. I'm not sure why the D&RGW #5654 would have to lead this train.