In 1907, the Walla Walla Valley Railway built a fourteen-mile electric railway from its terminal on 6th Street in downtown Walla Walla, Washington, to Milton-Freewater, Oregon. The company, which also operated the city streetcar system in Walla Walla, had joined a national frenzy of interurban railway construction.

The city railway began more modestly in 1890, when the Walla Walla Street Railway and Investment Company's pioneer horsecars started running from Second and Main Streets to Park Street in Walla Walla. That enterprise grew to six cars and four miles of track, but plans for electrification had not been fulfilled when operation ceased around 1899.

In 1902, the new Walla Walla City Railway was also unsuccessful in its effort to build an electric streetcar system in Walla Walla. Adequate power may not have been available prior to completion of a hydroelectric plant on the Walla Walla River on December 31, 1904.

Three years later, the newly incorporated Walla Walla Valley Traction Company agreed to build a street railway as part of a broader scheme to construct an interurban railroad to Oregon. On December 24, 1906, city trolley service began from the Oregon Railway and Navigation depot to City Park in Walla Walla. Two more Walla Walla streetcar lines were added in 1908, increasing city mileage to twelve.

On April 16, 1907, the Walla Walla Traction Company opened a fourteen-mile interurban line to the twin cities of Freewater and Milton, Oregon, located in the heart of the rich Walla Walla Valley fruit country. A freight business shipping carloads of fruit, dairy products, and wheat was quickly developed.

On April 30, 1910, the name of the railroad was changed to the Walla Walla Valley Railway, which was now part of the Pacific Power & Light Company. Passenger service, operated by only one man per car after 1916, was handled by seven semi-convertibles, two open trailers, two interurban coaches, and two combines.

Passenger service had not paid expenses for some time when the Northern Pacific Railway acquired the railway in 1921. The Prospect Heights and East Walla Walla streetcar lines in Walla Walla were discontinued on August 1, 1920, and the City Park line on December 31, 1926. Interurban service to Oregon ceased on September 2, 1931. The last owner of the line, Burlington Northern, abandoned the railroad in 1985.