Burlington Northern locomotive 5522 is on the loading loop at West Decker where empty cars are loaded with coal at the steady rate of 1/2 mph. Trains can be seen at the right and left. They serve the Power River mining district of southern Montana and Northern Wyoming, said to be largest coal district in the United States. The photograph appeared in the "Locomotive Engineer" of the BLE in January 5, 1979.
"Coal makes the Burlington Northern run at Sheridan, Wyoming," accordng to the BLE newspaper of January 5, 1979, and many "rails" are required to make that happen on what is now the Burington Northern Santa Fe.
The speed with which the coal cars are filled demanded refined technology, which is not visible in this photograph.
Cook intended this to be both a portrait of a locomotive and a panorama of the coal operation at West Decker, and he succeeded.