Pictured above is ARR 2-6-0 Mogul #242. Originally built as Isthmian Canal Commission # 242 (the I.C.C. were the builders of the Panama Canal)  Alco/Cooke builders # 39153 in 1906. Built as 5 foot gauge. Transferred to the ARR in 1923.  Converted to standard gauge.   Retired in January 1930.
An interesting footnote to #242s history is that it was involved in a major derailment.  On January 1, 1923, locomotives 242 and 221 were on a run from Seward to Anchorage.  At 5:00 a.m. they ran up on glacier ice on the rail at mile post 91.7.  Locomotive #242 left the track and ran over the bank to the tidal flats.  It was followed by a flat car loaded with ties which shifted and the ties piled up on the engine below.  The conductor of locomotive #242, Charles Odd, was badly scalded and died in the Railroad Hospital at Anchorage at 1:00 p.m.  The engineer and fireman were only slightly injured.
In the photo above, number 242 is leaving anchorage for Matanuska and Chickaloon.

Alaska Railroad photo, Jack Klingbeil collection