Nine Mile Hydroelectric Development, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

Significance: Completed in 1908, the Nine Mile hydroelectric facility was constructed by mining entrepreneur and capitalist Jay P. Graves for the purpose of developing and providing power to his electric railroad system, the Spokane and Inland Empire Railroad Company. Following a decline in the popularity of electric railway transportation systems in the 1920s, the Washington Water Power Company (WWP) acquired the Nine Mile facility in 1925. The facility is significant for the role it played in the development of the electric railway industry in eastern Washington, in the growth of agriculture and agricultural communities served by the railroad, and in the later expansion of the WWP's electrical transmission network throughout eastern Washington and northern Idaho. The ten operators' cottages (constructed in 1928-1930) that stand adjacent to (northwest of) the powerhouse and dam exemplify the residential component necessary for the operation of hydroelectric facilities in remote locations during the early twentieth century. Constructed in the Craftsman and English Cottage styles of the period, the cottages retain good exterior integrity, as does the powerhouse and dam. The powerhouse, dam, and operators' cottages are contributing elements in the Nine Mile Hydroelectric Power Plant Historic District, a property listed in the National Register of Historic Places in 1990.
Survey number: HAER WA-84
Building/structure dates: 1908 Initial Construction
National Register of Historic Places NRIS Number: 90001861