{"nrhp_refnum":"88000839","name":"Bridge in Gibson Borough","other_names":[],"category":"structure","location":{"address":"LR 57045 over Tunkhannock Creek","address_restricted":false,"city":"South Gibson","county":"Susquehanna County","state":"PA","lat":41.742164847000026,"lon":-75.63051144899998,"geom_source":"nps_gis"},"listed_date":"1988-06-22","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A single-span stone slab bridge in Gibson Borough, Susquehanna County, Pennsylvania, carrying vehicular traffic over Tunkhannock Creek. It is a rubble-construction structure with a stone slab on corbelled stone supports, 58 feet long by 25 feet wide, with an 8-foot overall span.","why_significant":"The nomination argues the bridge is a rare surviving example of the stone slab or clapper bridge type, regarded as the most primitive form of stone bridge. Its corbelled supports could be classified as a primitive corbelled, or false, arch. It is presented as an important example of early bridge construction in Pennsylvania, with significance in the area of engineering.","narrative":"A single-span stone slab bridge carries vehicular traffic over Tunkhannock Creek in Gibson Borough, Susquehanna County. The structure is built of dry, unmortared rubble stone, with a slab laid across stone supports that are corbelled inward. The span measures about 8 feet overall, and the nominated area covers the superstructure and substructure within the outside corners of the wing walls, measuring 58 feet long by 25 feet wide. The bridge is regarded as a rare surviving example of the stone slab or clapper bridge, the most primitive form of stone bridge. Because its corbelled supports form a primitive false arch, it is considered an important example of early bridge construction in Pennsylvania. Its significance lies in engineering. The construction date is not documented; state staff estimated it between 1775 and 1825, and the designer and builder are unknown.","period_of_significance":null,"architect_builder":null,"architectural_style":null,"criteria":[],"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 17:11:35.781617-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000839.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000839/a7d6e617fd-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000839/a7d6e617fd-1600.webp","licence":"Public domain","author":"PennDOT","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Bridge_in_Gibson_Borough.jpg\" rel=\"noopener\">PennDOT</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Bridge_in_Gibson_Borough.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993889","wikipedia":"https://en.wikipedia.org/wiki/Bridge_in_Gibson_Borough","wikidata":"https://www.wikidata.org/wiki/Q4966357"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/susquehanna-county/bridge-in-gibson-borough-88000839/"}