The Northern Pacific Depot at Portland, Oregon, circa 1880, from the Walter W. Ainsworth Collection.

Spokane, Portland & Seattle Railway steam locomotive number 700 at Prosser, Washington, in October 1990. SP&S passes signal 398 near Prosser on its way to Yakima, Washington, with an excursion train in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train.

Spokane, Portland & Seattle Railway steam locomotive number 700 near Prosser, Washington, in October 1990. SP&S 700 leads an excursion between Gibbon and Prosser in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train, river.

Spokane, Portland & Seattle Railway steam locomotive number 700 near Prosser, Washington, in October 1990. SP&S 700 leads an excursion between Gibbon and Prosser in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train, river.

Spokane, Portland & Seattle Railway steam locomotive number 700 near Prosser, Washington, in October 1990. SP&S passes signal 398 near Prosser on its way to Yakima, Washington, with an excursion train in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train, semaphore signal.

Spokane, Portland & Seattle Railway steam locomotive number 700 at Prosser, Washington, in October 1990. SP&S 700 passes the station at Prosser with an excursion train in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train.

Spokane, Portland & Seattle Railway steam locomotive number 700 near Prosser, Washington, in October 1990. SP&S 700 leads an excursion between Gibbon and Prosser in 1990. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive, passenger train, river.

Plat Map of Northern Pacific facilities at Prosser, Washington, undated, Sheet Number 2, Line Segment 48, showing the Pasco-Ellensburg line.

Plat Map of Northern Pacific facilities at Prosser, Washington, undated, Sheet Number 4, Line Segment 48, showing the Pasco-Ellensburg line.

Plat Map of Northern Pacific facilities at Prosser, Washington, undated, Sheet Number 1, Line Segment 48, showing the Pasco-Ellensburg line.