Allegheny River Lock and Dam No. 7
Why it's listed
Lock and Dam No. 7 is a navigation structure on the west bank of the Allegheny River at Kittanning, Pennsylvania, 45.7 miles above the river's mouth. The U.S. Army Corps of Engineers built it between 1928 and 1930, with Dravo Corporation as contractor, using standard designs adapted to the site. The complex includes a 56-by-360-foot lock with a 13-foot lift, a 916-foot fixed-crest dam, a concrete esplanade, and a two-story operations building that houses hydraulic pumps driven by water turbines. The dam's gravel-filled cylindrical sheet piling caused debate among Corps officials before stone was added downstream. The facility opened on November 10, 1930, and gave barges access to about 72 miles of the Allegheny. It is valued for its part in the river's transportation network and for preserving much of its original machinery and layout.
Significance in brief: The nomination argues the lock and dam is significant for its role in the Allegheny River navigation system, providing slackwater access to commercial barge and towboat traffic and to resources north of Kittanning. It is also presented as a representative example of lock and dam construction of 1928-1930, retaining its original appearance, machinery and function.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 00000401, listed April 21, 2000. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence high).
Key facts
| Address | Along PA 4023, 0.6 mi. N of Kittanning Br., Kittanning |
|---|---|
| County | Armstrong County |
| Listed | April 21, 2000 |
| Reference number | 00000401 |
| Resource type | Structure |
| Period of significance | 1903-1948 |
| Architect / builder | Dravo Corporation (contractor) |
| Architectural style | Late Nineteenth and Early Twentieth Century Revival |
| Criteria |
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| Areas of significance | Transportation, Maritime History, Architecture, Engineering |
| Level of significance | State |
| Status (as stated in the nomination) | In operation; alterations include gate and valve replacements, a gas heating system and a 1992-1994 renovation. |
| Acreage | 19.3 |
| Coordinates | 40.82048, -79.52880 (NPS GIS) |
What listing means for this property
For a publicly owned building or structure, listing mainly matters when federal funds, permits or licences are involved: projects then go through Section 106 review so effects on the property are considered. Listing also strengthens applications for preservation grants and, for leased income-producing uses, can enable the federal rehabilitation tax credit.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 00000401.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q4731340
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.