ALCO RSD-1 #1027 (builder number 70670) was built in 1943 for the US Army 8049.  The Alaska Railroad acquired it in 1949.  It was retired in 1971 and became ARR slug Mate 2 in 1972.  It was the only locomotive to come through the 1964 earthquake in Seward and remain in operating condition.
The above photo shows #1027 in the Anchorage Yard on 4/26/70.

Photo courtesy of Jack Klingbeil