Just one Alco unit 6011 and two passenger cars, made up the Denver to Craig "Yampa Valley Mail" leaving Denver on March 4, 1962. From my slide collection, Photo by Gordon B. Mott.

Rio Grande Alco PA-1 #6011 and F7B #5712 slowly accelerate from Denver Union Station with the southbound Royal Gorge on November 15, 1958. Photo from my slide collection, photographer Lou Schmitz.