River Mill Hydroelectric Project

River Mill Hydroelectric Project
River Mill dam c. 1911
River Mill Hydroelectric Project is located in Oregon
River Mill Hydroelectric Project
Location in Oregon
River Mill Hydroelectric Project is located in the United States
River Mill Hydroelectric Project
River Mill Hydroelectric Project (the United States)
Nearest cityEstacada, Oregon
Coordinates45°17′58″N 122°21′2″W / 45.29944°N 122.35056°W / 45.29944; -122.35056
Area5 acres (2.0 ha)
Built1911
ArchitectNils F. Ambursen, Puget Sound Bridge & Dredging Co.
Architectural styleHydroelectric facility
NRHP reference No.01000497[1]
Added to NRHPMay 10, 2001[1][2]

River Mill Hydroelectric Project, also known as River Mill Dam and Station M, is a hydroelectric dam and powerhouse in Clackamas County, Oregon, United States. It is just north of Estacada, Oregon, on the Clackamas River at river mile 23.5 (km 37.8). It received its name from being near a sawmill that was located along the river.[3]

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. 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.[4] All but Faraday, demolished 2018, are still owned and operated by the successor company, Portland General Electric.[5]

River Mill dam, view from east bank

The principal designer of the original Mill Run Dam was the Norwegian immigrant Nils F. Ambursen (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.[4]

The project is listed on the National Register of Historic Places, and in the Oregon Historic Sites Database of the Oregon State Historic Preservation Office.[6]

Governor in River Mill dam.
  1. ^ a b "National Register Information System". National Register of Historic Places. National Park Service. July 9, 2010.
  2. ^ "National Register of Historic Places Listings: May 18, 2001". National Park Service. Retrieved 2009-10-07.
  3. ^ McArthur, Lewis A. Oregon Geographic Names (3rd ed.). p. 513.
  4. ^ a b Kramer, George (2001). "River Mill Hydroelectric Project" (PDF). National Park Service. Retrieved 2016-01-03.
  5. ^ "Clackamas River Photo Tour: River Mill". Portland General Electric. Archived from the original on 2010-01-02. Retrieved 2009-10-07.
  6. ^ "Oregon Historic Sites Database: River Mill Hydroelectric Project". Oregon Parks and Recreation Department. Retrieved 2009-10-07.