The Spokane, Portland & Seattle Railroad began in 1900 as a dream of James J. Hill. Hill owned Great Northern, Northern Pacific and Chicago Burlington & Quincy and he sought to reach the Pacific. This dream started life as the Portland & Seattle Railroad and was to connect the Hill roads from Spokane to the Pacific. Union Pacific and Southern Pacific fought hard to keep Hill out of their territory in Oregon, but in 1908 the railroad was completed and renamed the Spokane, Portland & Seattle Railway.
Aftern the completion of its main line in 1909, they extended down into Oregon via acquisitions. SP&S acquired the Oregon Electric Railway in 1910, extending it down into Salem
Through the SP&S, Hill was able to make moves deep into Oregon towards California. Via the Oregon Electric branch line, the SP&S linked southward to Eugene, and via the Oregon Trunk, the SP&S linked Wishram to Bend in central Oregon. The overall goal of reaching California was reached much later in conjunction with the Western Pacific.
The SP&S was mainly used to haul grain west and lumber east. As the SP&S was a railroad jointly owned by the NP and GN, they mainly used second hand equipment. The arrival of the Z6 mallets in 1937 and the E1 northerns in 1938 marked the first influx of new power into the SP&S system since its inception. When the mallets arrived in Vancouver, the firebox was so large that a banquet was thrown inside of one of them.
During World War II, the SP&S was provided a traffic boost due to war material movement. They were also the beneficiary of cheap electric power from the Columbia River Dams. The cheap electricity also attracted major aluminum plants, sawmills, chemical factories and grain terminals along the line. All of this extra traffic kept SP&S going strong throughout the War.
Also during the War, dieselization began taking place. First was the Alco and Baldwin switchers taking yard duty over. SP&S ran primarily Alcos throughout the diesel era, so much so that they are still synonymous with Alco RS3s, FAs and Century 424s.
The days of the SP&S operating as a separate entity were coming to an end as by the mid 1960s, it became clear that the parent companies intended to merge. This came to fruition in 1970 with the formation of the Burlington Northern. The most enduring legacy of the SP&S remains the water level route along the Columbia River. That line is still the primary Pacific Northwest mainline of the BNSF.