{"nrhp_refnum":"82003600","name":"Keystone Furnace","other_names":[],"category":"district","location":{"address":null,"address_restricted":true,"city":"Pattonsville","county":"Jackson County","state":"OH","lat":null,"lon":null,"geom_source":null},"listed_date":"1982-03-18","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Historic - Non-Aboriginal","Transportation","Exploration/Settlement"],"significance_levels":["state"],"summary":null,"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71989441","wikipedia":null,"wikidata":null},"indexable":false,"url":"https://nationalhistoricalregister.com/ohio/jackson-county/keystone-furnace-82003600/"}