{"nrhp_refnum":"66000656","name":"Johnstown Flood National Memorial","other_names":[],"category":"structure","location":{"address":"Jct. of U.S. 219 and PA 869","address_restricted":false,"city":"Johnstown","county":"Cambria County","state":"PA","lat":40.34178827200003,"lon":-78.77972336299996,"geom_source":"nps_gis"},"listed_date":"1966-10-15","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Other"],"significance_levels":["national"],"summary":{"what_it_is":"The Johnstown Flood National Memorial is a 163-acre park in Croyle and Adams Townships, Cambria County, Pennsylvania, containing the remnants of the South Fork Dam, built by the Commonwealth of Pennsylvania between 1838 and 1853, along with the Elias J. Unger House and related farm buildings.","why_significant":"The failure of the South Fork Dam on May 31, 1889 caused the most notable and devastating flood of the nineteenth century in the United States, with over 2,200 lives lost and more than $17 million in property damage. The nomination argues the event gave rise to a large body of literature and offers lessons for engineering and environmental management. The Unger House and outbuildings are significant for their link to Elias J. Unger, a club president who was at the property during the flood.","narrative":"Dam remnants and farm buildings in Cambria County, Pennsylvania, make up this park. The South Fork Dam was built by the Commonwealth of Pennsylvania between 1838 and 1853 to supply water to the Western Division of the Pennsylvania Main Line Canal. In 1879 a group of Pittsburgh industrialists formed the South Fork Fishing and Hunting Club and purchased the dam and reservoir, which was renamed Lake Conemaugh, for a summer resort. On May 31, 1889, heavy rains raised the lake beyond safe levels, and the poorly reconstructed dam failed, sending a wall of water down the valley into Johnstown. The disaster caused more than 2,200 deaths and over $17 million in property damage. The park preserves the earthen abutments, the spillway, and the sluice foundation. The Elias J. Unger House, built around the mid-1880s, stands nearby, and it is linked to the disaster through Unger's actions on the morning of the flood.","period_of_significance":"1838-1889","architect_builder":null,"architectural_style":"Vernacular version of the Gothic Revival style (Unger House)","criteria":["A","B","C","D"],"status_note":"Dam remains are largely abutments and foundations; the Unger House is stabilized with a temporary roof; the spring house is collapsing; the main barn and carriage shed have collapsed into ruins.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:29.855618-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/66000656.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000656/646b2c12ce-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000656/646b2c12ce-1600.webp","licence":"CC BY-SA 2.0","author":"David Brossard","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:What_remains_of_the_South_Fork_Dam_(11717678065).jpg\" rel=\"noopener\">David Brossard</a>, <a href=\"https://creativecommons.org/licenses/by-sa/2.0\" rel=\"license noopener\">CC BY-SA 2.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:What_remains_of_the_South_Fork_Dam_(11717678065).jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71998256","wikipedia":"https://en.wikipedia.org/wiki/Johnstown_Flood_National_Memorial","wikidata":"https://www.wikidata.org/wiki/Q6268782"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/cambria-county/johnstown-flood-national-memorial-66000656/"}