The Spokane, Portland and Seattle Railway was a United States-based railroad incorporated in 1905. It was a joint venture by the Great Northern Railway and the Northern Pacific Railway to build a railroad along the north bank of the Columbia River.
In 1909 construction of the Oregon Trunk to Bend, Oregon began. This line constituted part of the "Inside Gateway" between Washington and California which the parent roads hoped to use to compete with Southern Pacific Railroad who virtually monopolized North-South traffic up to that time.
In 1910 it purchased the Oregon Electric Railway.
In 1970, it merged with the Great Northern Railway, the Northern Pacific Railway, and the Chicago, Burlington and Quincy Railroad to form the Burlington Northern Railroad. The Burlington Northern continued to operate it until 1987, when it announced intention to vacate the right-of-way between Snake River Junction (near Ice Harbor Dam) and Cheney. The segment between Portland and Pasco continues to serve successor BNSF and enjoys heavy traffic due to its low-grade and slight curvature crossing of the Cascade Range.
In 1991, the Washington State Parks system acquired the right-of-way and established the Columbia Plateau Trail State Park This park is a 4,109-acre, 130-mile-long rail-bed trail that traces that portion of the 1908 route of the Spokane, Portland and Seattle Railroad between Cheney and Ice Harbor Dam on the Snake River.