River Mill Hydroelectric Project, also known as River Mill Dam and Station M, is a

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

dam and powerhouse in

Clackamas County, Oregon Clackamas County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 421,401, making it Oregon's third-most populous county. Its county seat is Oregon City. The county was named after the Native ...

, United States. It is just north of

Estacada, Oregon Estacada is a city in Clackamas County, Oregon, United States, about southeast of Portland. The 2020 population is estimated to be 3,700. According to the 2010 census, the population in 2010 was 2,695. It is the 89th largest city in Oregon and t ...

, on the

Clackamas River The Clackamas River is an approximately tributary of the Willamette River in northwestern Oregon, in the United States. Draining an area of about , the Clackamas flows through mostly forested and rugged mountainous terrain in its upper reaches, a ...

river mile A river mile is a measure of distance in miles along a river from its mouth. River mile numbers begin at zero and increase further upstream. The corresponding metric unit using kilometers is the river kilometer. They are analogous to vehicle road ...

23.5 (km 37.8). It received its name from being near a sawmill that was located along the river. The dam has been in continuous production of hydroelectric power since 1911, when its construction was funded by the

Portland Railway, Light and Power Company The Portland Railway, Light and Power Company (PRL&P) was a railway company and electric power utility in Portland, Oregon, United States, from 1906 until 1924.Thompson, Richard M. (2006). ''Portland's Streetcars'', pp. 57 and 99. Arcadia Publis ...

. It was one of four related projects on the Clackamas River: the Oak Grove Hydroelectric Project (developed 1923–56), the North Fork dam (1958), and the Faraday Dam (1907–10), all upstream (south) of River Mill. All but Faraday, demolished 2018, are still owned and operated by the successor company,

Portland General Electric Portland General Electric (PGE) is a Fortune 1000 public utility based in Portland, Oregon. It distributes electricity to customers in parts of Multnomah, Clackamas, Marion, Yamhill, Washington, and Polk counties - 44% of the inhabitants of O ...

The principal designer of the original Mill Run Dam was the Norwegian immigrant

Nils F. Ambursen Nils F. Ambursen (February 6, 1876 – January 17, 1953) was a Norwegian-American civil engineer and inventor. He was the founder of Ambursen Hydraulic Construction Company and was known for his influential dam designs in the early 20th century ...

(1876–1958). Based in Boston, his Ambursen Hydraulic Construction Company designed over a hundred dams in the United States from 1903 through 1917. Ambursen's patented concrete-slab-and-buttress dam design was a significant advance in dam design of this era. River Mill is one of only three Ambursen-type dams built west of the Mississippi, and evidently the only one to survive. The project is listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic v ...

, and in the Oregon Historic Sites Database of the

Oregon State Historic Preservation Office The Oregon Parks and Recreation Department (OPRD), officially known (in state law) as the State Parks and Recreation Department, is the government agency of the U.S. state of Oregon which operates its system of state parks. In addition, it has pro ...

References

External links

* {{National Register of Historic Places Energy infrastructure completed in 1911 National Register of Historic Places in Clackamas County, Oregon Buildings and structures in Clackamas County, Oregon Dams in Oregon Portland General Electric dams Hydroelectric power plants in Oregon 1911 establishments in Oregon Dams on the National Register of Historic Places in Oregon Industrial buildings and structures on the National Register of Historic Places in Oregon Energy infrastructure on the National Register of Historic Places