{"nrhp_refnum":"00000402","name":"Allegheny River Lock and Dam No.8","other_names":[],"category":"structure","location":{"address":"Along PA 1033, 1.5 mi. S of Templeton","address_restricted":false,"city":"Templeton","county":"Armstrong County","state":"PA","lat":40.89570225950007,"lon":-79.48007741689219,"geom_source":"nps_gis"},"listed_date":"2000-04-21","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Maritime History","Architecture","Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A U.S. Army Corps of Engineers lock and dam on the Allegheny River at Templeton, Armstrong County, Pennsylvania, 52.6 miles upstream from the river's mouth. It includes the lock, dam, esplanade, an operations building (powerhouse) and two locktenders' houses.","why_significant":"The nomination argues the lock and dam are significant for their role in the Allegheny River slackwater navigation system, which gave barge access to the Harbison-Walker refractory brick operations at Templeton. It also argues the facility is a representative example of lock and dam construction of 1929-1931 that retains its original appearance, machinery and function.","narrative":"Built on the south bank of the Allegheny River near Templeton, the lock and dam were constructed by the U.S. Army Corps of Engineers between 1929 and 1931, with a contract let in 1929 and the facility opening on May 21, 1931. The concrete lock measures 56 by 360 feet and lifts vessels 17.8 feet, while the 933-foot dam was raised three feet in 1937 to become a fixed crest structure. It was built to provide slackwater navigation for commercial barges and towboats over 72 miles of river, including access to the Harbison-Walker refractory brick plant at Templeton, described as one of the largest brick plants in North America. The operations building, a two-story powerhouse, still houses original hydraulic pumps driven by water turbines, though its exterior was pargeted around 1990. The property is regarded as a representative example of lock and dam construction of its period, retaining much of its original design, machinery and layout.","period_of_significance":"1903-1948","architect_builder":"U.G.I Contracting Company (contractor)","architectural_style":"Late 19th and early 20th century revival","criteria":["A","C"],"status_note":"Operating; a low-head hydroelectric plant was added in 1990 and remains in operation.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:36.2843-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/00000402.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/00000402/5c63017154-800.webp","url_1600":"https://nationalhistoricalregister.com/media/00000402/5c63017154-1600.webp","licence":"CC BY-SA 3.0","author":"Generic1139","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Allegheny_River_Lock_and_Dam_No._8_wide.jpg\" rel=\"noopener\">Generic1139</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Allegheny_River_Lock_and_Dam_No._8_wide.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992264","wikipedia":"https://en.wikipedia.org/wiki/Allegheny_River_Lock_and_Dam_No._8","wikidata":"https://www.wikidata.org/wiki/Q4731341"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/armstrong-county/allegheny-river-lock-and-dam-no-8-00000402/"}