The locomotive was used for passenger service for the Union Pacific railroad.
The UP ordered the last ten in 1944 (#835-#844), which were designated Class FEF-3.
UP 838 was retired from service on July of 1962 and it was stored at the UP's Cheyenne, Wyoming roundhouse in Cheyenne, Wyoming in 1977.
As of today the engine is stored at the UP's Cheyenne, Wyoming roundhouse.
The reason that #838 is put in storage at the Cheyenne Roundhouse it's because of the Source of spare parts for 844.
No. 838's running gear and boiler are in much better condition due to 844's extensive use.