SP&S 4-6-6-4 steam locomotive Number 901, Class Z-6, with an eastbound freight departing Pasco, Washington on May 9, 1938. Photo by Al Farrow.

SP&S 4-6-6-4 steam locomotive Number 901, Class Z-6, departing with a freight train from Pasco, Washington on May 9, 1938.

SP&S 4-6-6-4 steam locomotive Number 902, Class Z-6, leaving Pasco, Washington as Extra 902 West, September 2, 1954. Photo by Al Farrow.

SP&S 4-6-6-4 steam locomotive Number 903, Class Z-6, leaving Pasco, Washington with Train Number 275, March 21, 1939. This locomotive would later become Great Northern Number 4000. Photo by Al Farrow.

SP&S 4-6-6-4 steam locomotive Number 905, Class Z-6, arriving with a freight train at Pasco, Washington on June 1, 1941.

Titan Railway Services (TITAN) diesel locomotive 1200, a Class SW1200 at Pasco, Washington, 1995. Other Subject Classes: Locomotive-Diesel

Titan Railway Services (TITAN) diesel locomotive 7, a General Electric Class 25 T at Pasco, Washington, 1996. Other Subject Classes: Locomotive-Diesel

Titan Railway Services (TITAN) diesel locomotive 7, a General Electric Class 25 T at Pasco, Washington, September 16, 1995. Other Subject Classes: Locomotive-Diesel

United States Navy 0-4-0T steam locomotive number 6992 parked at Pasco, Washington, on September 24, 1948. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, switching locomotive.

Washington State Railroads Historical Society (WSRHS) diesel locomotive 5933, a Class GP7 at Pasco, Washington, June 1998. Other Subject Classes: Locomotive-Diesel