Nine Mile Dam, Hydroelectric dam in Nine Mile Falls, Washington, United States.

Nine Mile Dam is a 58-foot-high cyclopean masonry dam on the Spokane River in Nine Mile Falls, Washington. It was built in 1908, creating Nine Mile Reservoir, and its powerhouse stands on a basalt bluff downstream. The dam is one of six hydroelectric plants operated by Avista.

The facility was built in 1908 by the New York engineering firm Sanderson & Porter to supply power for the Spokane and Inland Empire Railroad interurban lines. This early hydroelectric development was part of regional railroad expansion.

The ten brick cottages date from 1928 and 1929, not 1928 alone, and were built by Washington Water Power as housing for dam employees. Each one-story cottage has three bedrooms, a kitchen, a bathroom and a living room, a small garage in the back yard, and a large front porch. The row sits on a basalt bluff downstream of the dam, along a tree-lined road leading southwest to the powerhouse.

The site is most easily reached from the main road through Nine Mile Falls, with visible access to the dam and surrounding cottages. Visit in clear weather to best see the reservoir and surrounding landscape.

The cottages sit on the downstream side of the dam, on a basalt bluff above the Spokane River, and each has a small garage in its back yard. They were built in 1928 and 1929, when Nine Mile was still remote from Spokane's residential areas.