{"nrhp_refnum":"04000464","name":"Cheoah Hydroelectric Development","other_names":[],"category":"district","location":{"address":"1512 Tapoca Rd., NC 129","address_restricted":false,"city":"Robbinsville","county":"Graham County","state":"NC","lat":35.45024260900004,"lon":-83.93586486555381,"geom_source":"nps_gis"},"listed_date":"2004-05-21","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Architecture","Industry"],"significance_levels":["local"],"summary":{"what_it_is":"A hydroelectric development on the Little Tennessee River in Graham and Swain Counties, North Carolina, consisting of a concrete arched dam, powerhouse, penstock building, gatehouses, tram bridge and a Cheoah River bridge. Construction ran from 1916 to 1919 and it was built by Alcoa.","why_significant":"The nomination argues the development is significant under criterion A for its role in the industrial development of the region, supplying power to Alcoa's aluminum plants in Tennessee. It is also significant under criterion C for its engineering, as the dam was the highest overflow dam in the world when completed and its turbines were the largest in existence. The nomination states that the design became a model for later dams.","narrative":"Built on the Little Tennessee River between 1916 and 1919, the Cheoah Hydroelectric Development was the first of four Alcoa-built facilities in the Tapoco Hydroelectric Project. The complex includes a gravity-type concrete arched dam 225 feet high and 750 feet long, a reinforced concrete powerhouse, a penstock building, two concrete gatehouses and a steel gantry crane. Operation began in April 1919, and the dam was then the highest overflow dam in the world, while its powerhouse held the largest hydroelectric generating units. The power generated was carried 28 miles by transmission lines to the aluminum reduction plant at Alcoa, Tennessee. A fifth turbine was added in 1949. The development is significant for its engineering design and its role in supplying electricity to the regional aluminum industry. Its original concrete surfaces and powerhouse windows remain largely intact.","period_of_significance":"1919-1953","architect_builder":"Power & Engineering Group of Alcoa, Pittsburgh, PA","architectural_style":"Late 19th & early 20th century revivals / Classical Revival","criteria":["A","C"],"status_note":null,"vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:42.698432-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/49/7178/47717849/content/electronic-records/rg-079/NPS_NC/04000464.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/04000464/3d3fd69279-800.webp","url_1600":"https://nationalhistoricalregister.com/media/04000464/3d3fd69279-1600.webp","licence":"Public domain","author":"own work","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:CheoahDam.JPG\" rel=\"noopener\">own work</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:CheoahDam.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/47717849","wikipedia":"https://en.wikipedia.org/wiki/Cheoah_Dam","wikidata":"https://www.wikidata.org/wiki/Q723194"},"indexable":true,"url":"https://nationalhistoricalregister.com/north-carolina/graham-county/cheoah-hydroelectric-development-04000464/"}