At first I didn't know what the engine was: an E3 or an E6. But when I had a closer look at the large image, I found the little square box atop the cab windows. It says "15". ATSF 15 was an EMD E6, one of 7 built in 1940 and 1941.
I did some research and found out that the earlier E3 has the same shovel nose, but a total different roof configuration.
This image is simply stunning. One of the best early Santa Fe pictures I know. This image was also published in the Winter 2008 issue of Classic Trains.
Photo: Jack Delano, March 1943
Library of Congress
Description: Santa Fe R.R. streamliner, the "Super Chief," being serviced at the depot, Albuquerque, New Mexico. Servicing these diesel streamliners took five minutes.
I'd like to recommend you to view this picture at full size. The detail on this image is amazing. Just look at the cars on the left.