Allegheny River Lock and Dam No. 9

Rimer Road N of Scenic Rd, Widnoon, PA


Photo taken by Brian Manville on May 22, 2017



Allegheny River Lock 9

YouTube user TCulley77

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Allegheny River Lock and Dam No. 9 is a historic lock and dam complex located at Madison and Washington Townships in Armstrong County, Pennsylvania. It was built between 1935 and 1938 by the United States Army Corps of Engineers and includes the lock, dam, steel miter gates, and operations building. The lock measures 56 feet by 360 feet, and has a lift of 22 feet. The dam measures approximately 60 feet high and 918 feet long. The operations building, or powerhouse, is a utilitarian two-story building in a vernacular early-20th century revival style. The lock and dam were built by the U.S. Army Corps of Engineers as a part of an extensive system of locks and dams to improve navigation along the Allegheny River.

National Register information 

Posted to the National Register of Historic Places on April 21, 2000
Reference number
Architectural style
Late 19th and 20th Century Revival
Areas of significance
Transportation; Maritime History; Architecture; Engineering
Level of significance
Evaluation criteria
A - Event; C - Design/Construction
Property type
Historic function
Current function
Periods of significance
1900-1924; 1925-1949
Significant years
1937; 1938
Number of properties
Contributing buildings: 4
Contributing structures: 3
Non-contributing structures: 1

Update Log 

  • May 22, 2017: Updated by Brian Manville: Added photographs, video and description from Wikipedia
  • May 22, 2017: New photos from Brian Manville



Allegheny River Lock and Dam No. 9
Posted May 24, 2017, by Brian Manville

Army Corps of Engineers contemplates tearing out lightly used locks, dams on upper Allegheny