{"nrhp_refnum":"90000391","name":"Frehn Bridge","other_names":["Huntingdon County Bridge #1"],"category":"structure","location":{"address":"Twnshp. Rt. 313, 2 mi. W of PA 475","address_restricted":false,"city":"Springfield","county":"Huntingdon County","state":"PA","lat":40.13345036700008,"lon":-77.99101727599998,"geom_source":"nps_gis"},"listed_date":"1990-03-20","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A 120-foot, single-span, pin-connected Pratt through truss bridge with a 13.75-foot-wide timber deck, spanning Sideling Hill Creek in southern Springfield Township, Huntingdon County, Pennsylvania. It has original gravity-type concrete abutments and wing walls.","why_significant":"The nomination argues the bridge is a fine example of one of fewer than ten remaining pin-connected Pratt through truss bridges in the county, likely built in the late 1800s. It retains integrity of material, design and setting, and is important locally in the area of engineering.","narrative":"Pin-connected Pratt through truss bridges of this type were once common in Pennsylvania, and the Frehn Bridge is one of fewer than ten remaining examples in Huntingdon County. The single-span structure crosses Sideling Hill Creek in southern Springfield Township and measures 120 feet long, with a 13.75-foot-wide timber deck. Its abutments and wing walls are original gravity-type concrete rather than reinforced concrete, which the nomination identifies as a sign of its early construction. The steel truss, timber deck and substructure together retain integrity of material, design and setting. The bridge sits in a rural area in the southern part of the county and is dated to around 1890. Its builder and the details of its construction are not known, as the county bridge office and commissioners' records hold no contract or history for it. It is regarded as locally important for its engineering.","period_of_significance":"c.1890","architect_builder":null,"architectural_style":null,"criteria":["C"],"status_note":"The bridge has been well maintained.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:37.987815-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/90000391.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/90000391/78491209ac-800.webp","url_1600":"https://nationalhistoricalregister.com/media/90000391/78491209ac-1600.webp","licence":"Public domain","author":"Nancy Shedd for HABS/HAER","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Frehn_Bridge_HABS.jpg\" rel=\"noopener\">Nancy Shedd for HABS/HAER</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Frehn_Bridge_HABS.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993023","wikipedia":"https://en.wikipedia.org/wiki/Frehn_Bridge","wikidata":"https://www.wikidata.org/wiki/Q5501328"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/huntingdon-county/frehn-bridge-90000391/"}