{"nrhp_refnum":"88000762","name":"County Bridge No. 171","other_names":[],"category":"structure","location":{"address":"Cedar Hollow Rd. over Valley Creek","address_restricted":false,"city":"Malvern","county":"Chester County","state":"PA","lat":40.05355990500004,"lon":-75.50048905999995,"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":"County Bridge No. 171, a stone arch bridge over Valley Creek on Cedar Hollow Road in Tredyffrin Township, Chester County, Pennsylvania. It was built in 1907 by local contractors P. J. McCormick & Sons.","why_significant":"The nomination identifies the bridge as one of three stone arch bridges in the group with brick arch rings, alongside Brower's Bridge and Marshall's Bridge. Its overall form is similar to 19th century highway bridges, and it is described as showing high quality of design and construction with excellent integrity. The area of significance is engineering.","narrative":"Built in 1907 by the local contractors P. J. McCormick & Sons, this stone arch bridge carries Cedar Hollow Road over Valley Creek in Tredyffrin Township, Chester County. It has a single larger central span flanked by smaller spans, with a total length of about 100 feet and a width of about 25 feet. The structure is built of coursed rubble stone with brick arch rings and brick intrados and voussoirs, and it has contrasting coping stones on the parapets. It is one of three bridges in its group by the McCormick firm that share this combination of stone and brick, the others being Brower's Bridge and Marshall's Bridge. Its general form resembles nineteenth-century highway bridges. The bridge is valued for the quality of its engineering and design, and it retains excellent integrity. A plaque on the bridge records the date of construction.","period_of_significance":null,"architect_builder":"P. J. McCormick & Sons (builder/contractor)","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 17:11:36.355946-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000762.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000762/8f7e246957-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000762/8f7e246957-1600.webp","licence":"Public domain","author":"PennDOT","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:County_Bridge_No._171.jpg\" rel=\"noopener\">PennDOT</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:County_Bridge_No._171.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992666","wikipedia":"https://en.wikipedia.org/wiki/County_Bridge_No._171","wikidata":"https://www.wikidata.org/wiki/Q5177631"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/chester-county/county-bridge-no-171-88000762/"}