{"nrhp_refnum":"80003621","name":"Thomas Mill Covered Bridge","other_names":["See Also:Fairmount Park"],"category":"structure","location":{"address":"Thomas Mill Rd.","address_restricted":false,"city":"Philadelphia","county":"Philadelphia","state":"PA","lat":40.07172518100003,"lon":-75.22548652099994,"geom_source":"nps_gis"},"listed_date":"1980-12-01","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["national"],"summary":{"what_it_is":"A covered bridge crossing the Wissahickon Creek in Fairmount Park, Philadelphia, measuring 86 feet 6 inches long and 18 feet 8 inches wide. It was built in 1855 and repaired by the city in 1939.","why_significant":"The form states that the bridge is the oldest and longest of Pennsylvania's four remaining Howe-truss covered bridges and the only covered bridge in Philadelphia County. Its portals have unusual saw-toothed decorations.","narrative":"Spanning Wissahickon Creek within Fairmount Park in Philadelphia, this wooden covered bridge was built in 1855 and repaired by the city in 1939. It is a Howe truss structure measuring 86 feet 6 inches in length and 18 feet 8 inches in width. Its portals carry unusual saw-toothed decorations. The bridge is regarded as the oldest and longest of the four surviving Howe-truss covered bridges in Pennsylvania, and it is the only covered bridge in Philadelphia County. It is closed to traffic. The builder and architect are not identified in the available record, and the bridge's significance rests on its age, its truss type, and its rarity within the city and the state.","period_of_significance":null,"architect_builder":null,"architectural_style":"Howe truss","criteria":[],"status_note":"Closed to traffic","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:32.730532-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/80003621.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/80003621/6befa73c15-800.webp","url_1600":"https://nationalhistoricalregister.com/media/80003621/6befa73c15-1600.webp","licence":"Public domain","author":"Jack Boucher","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Covered_Bridge,_Thomas_Mill_Road_(Spanning_Wissahickon_Creek),_Philadelphia_(Philadelphia_County,_Pennsylvania).jpg\" rel=\"noopener\">Jack Boucher</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Covered_Bridge,_Thomas_Mill_Road_(Spanning_Wissahickon_Creek),_Philadelphia_(Philadelphia_County,_Pennsylvania).jpg"},"district":{"nrhp_refnum":"72001151","name":"Fairmount Park","url":"https://nationalhistoricalregister.com/districts/pennsylvania/fairmount-park-72001151/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993809","wikipedia":"https://en.wikipedia.org/wiki/Thomas_Mill_Covered_Bridge","wikidata":"https://www.wikidata.org/wiki/Q7792456"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/philadelphia/thomas-mill-covered-bridge-80003621/"}