SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, in storage at Vancouver, Washington in October 1956.

SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, at Vancouver, Washington in August 1953. Photo by Stan Styles.

SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, at Vancouver, Washington in April 1953. Photo by Stan Styles.

A crew member poses in front of SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, at an unknown location and date.

SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, at the Northern Pacific servicing facilities at Parkwater in Spokane, Washington on June 5, 1952. Photo by Don Roberts.

SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, at Spokane, Washington in June 1948.

SP&S 4-6-6-4 steam locomotive Number 904, Class Z-6, on the Oregon Trunk Railway at Madras, Oregon on August 15, 1939. On October 20, 1939 the locomotive was sold to Great Northern where it became GN 4001. On July 1, 1946 GN sold the locomotive back to SP&S and it received its original number 904.

SP&S 4-6-6-4 steam locomotive Number 903, Class Z-6, in storage at Vancouver, Washington on September 9, 1956. Photo by John Labbe.

SP&S 4-6-6-4 steam locomotive Number 903, Class Z-6, out of service at Vancouver, Washington in October 1956.

SP&S 4-6-6-4 steam locomotive Number 903, Class Z-6, out of service at Vancouver, Washington in August 1956. Photo by Stan Styles.