Warrior Ridge Dam and Hydroelectric Plant
Why it's listed
Warrior Ridge Dam and hydroelectric plant sits in a gap between two ridges of the Allegheny Mountains on the Frankstown Branch of the Juniata River, Huntingdon County. The main dam, a 400-foot reinforced concrete hollow dam about 27 feet high, was completed in 1905-07 for the Juniata Hydro-Electric Company of Philadelphia, with an auxiliary dam of similar design built in 1907. Ambursen Hydraulic Construction Company designed and built the dam, using a buttressed hollow-core form it had patented in 1904. William H. Cushman, the company's chief engineer, designed the power house. The plant had a rated capacity of 8000 horsepower and supplied power to Huntingdon, Altoona and Tyrone. The nomination treats the dam as an early prototype of its type and the complex, including four company houses built in 1907 for operators, as an intact example of an industrial facility and its community. A major part of the powerhouse was demolished in 1978.
Significance in brief: The nomination argues the complex is significant as an early prototype of buttressed hollow-core dam design by Ambursen, one of the earliest covered examples of that type, which drew wide attention in the engineering press. It is also presented as an intact industrial complex with its associated company housing, and as the first and only large-scale electricity production in Huntingdon County at that time.
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 90000701, listed April 26, 1990. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence high).
Key facts
| Address | 2 mi. S of Petersburg, along Conrail main line, Petersburg |
|---|---|
| County | Huntingdon County |
| Listed | April 26, 1990 |
| Reference number | 90000701 |
| Resource type | District |
| Period of significance | 1905-1939 |
| Criteria |
|
| Areas of significance | Engineering, Industry |
| Level of significance | Local |
| Status (as stated in the nomination) | A major portion of the power plant was demolished in 1978; the Agnes Flood of 1972 destroyed its turbines; the substation is in use; repairs since 1985 included new generators and a transformer. |
| Acreage | 8 |
| Coordinates | 40.54035, -78.03417 (NPS GIS) |
What listing means for this property
This is a historic district. Buildings within its boundary are either contributing (they add to the district's significance) or non-contributing. Owners of contributing income-producing buildings can claim the 20% federal rehabilitation tax credit; homeowners should look at state credits. National Register districts impose no design review by themselves; a local historic district ordinance, if one exists, does (the difference explained).
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 90000701.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q7970784
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.