{"nrhp_refnum":"88000865","name":"Allenwood River Bridge","other_names":[],"category":"structure","location":{"address":"LR 460 over W branch of Susquehanna River","address_restricted":false,"city":"Allenwood","county":"Northumberland County","state":"PA","lat":41.10776001000005,"lon":-76.88991034799994,"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 five-span pin-connected Pratt through truss bridge carrying vehicular traffic over the West Branch Susquehanna River at Allenwood, Northumberland County, Pennsylvania. It was built in 1895 by the Groton Bridge and Manufacturing Company of Groton, New York.","why_significant":"The nomination describes the bridge as a typical example of a multiple-span Pratt through truss and a well-preserved example of a bridge type frequently used in north central Pennsylvania. It is also cited as work by a nationally prominent bridge manufacturer. The area of significance is engineering.","narrative":"Built in 1895 by the Groton Bridge and Manufacturing Company of Groton, New York, the Allenwood River Bridge crosses the West Branch Susquehanna River in Northumberland County, Pennsylvania. It consists of five pin-connected through trusses, four of them with eleven panels at 17 feet and one longer main span of 210 feet, for an overall length of 970 feet. The trusses are built from channels, eyebars and lacing bars, and the steel superstructure was supplied by Jones & Laughlin. The piers, abutments and wing walls are coursed ashlar stone masonry. The bridge is regarded as a typical multiple-span Pratt truss and a well-preserved example of a bridge type common in north central Pennsylvania. It also represents the work of a nationally prominent bridge manufacturer. Alterations recorded since construction include a new wing in 1946, a new steel railing in 1954 and a rehabilitation in 1962. The bridge still carries vehicles across the river.","period_of_significance":"1895","architect_builder":"Groton Bridge and Manufacturing Company, Groton, New York (builder/contractor)","architectural_style":"Pratt through truss","criteria":[],"status_note":"Vehicular use is noted as present; the document lists alterations in 1946 (new wing), 1954 (new steel railing) and 1962 (rehabilitation).","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:36.332608-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000865.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000865/cc545d56c4-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000865/cc545d56c4-1600.webp","licence":"Public domain","author":"Robert C. Shelley","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Allenwood_River_Bridge.jpg\" rel=\"noopener\">Robert C. Shelley</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Allenwood_River_Bridge.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993414","wikipedia":"https://en.wikipedia.org/wiki/Allenwood_River_Bridge","wikidata":"https://www.wikidata.org/wiki/Q4732084"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/northumberland-county/allenwood-river-bridge-88000865/"}