{"nrhp_refnum":"88000869","name":"Pithole Stone Arch","other_names":[],"category":"structure","location":{"address":"LR 60046 over Pithole Creek","address_restricted":false,"city":"Oleopolis","county":"Venango County","state":"PA","lat":41.48696774000007,"lon":-79.59529272899994,"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 arch bridge carrying a vehicular road over Pithole Creek in Cornplanter and President Township, Venango County, Pennsylvania, on Crossing LR 60046 in a rural setting. It was built in 1897.","why_significant":"The nomination argues the bridge is a very fine example of a late nineteenth century stone arch bridge with high quality craftsmanship. Its arch is unusually shallow, a low rise-span form that was not commonly built because it produces greater horizontal thrust. The nomination notes the design avoids stone parapet walls to reduce dead load, with a projecting stone course capping the arch instead.","narrative":"Built in 1897 over Pithole Creek in rural Venango County, the Pithole Stone Arch is a single-span vehicular bridge of coursed ashlar masonry. Its span is 34 feet, and the carriageway rests directly on the arch ring, which makes the structure look flatter than most stone arches of its era. Builder R.A. Bigley used large, dressed stones for the arch ring, spandrel walls and wingwalls, and the bridge has a projecting stone course in place of a parapet. The nomination identifies the shallow profile as the main reason for its importance. A low rise-to-span ratio produces strong horizontal thrust, which required massive abutments and created risk of settlement, so few bridges of this form were built. The nomination also treats the workmanship as unusually good for a rural road. The downstream metal railing replaces an earlier railing, and a wingwall was replaced in 1974.","period_of_significance":"1897","architect_builder":"R.A. Bigley (builder)","architectural_style":null,"criteria":[],"status_note":"Replaced wingwall in 1974; the form records the bridge as altered.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:35.880827-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000869.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000869/e45f975d77-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000869/e45f975d77-1600.webp","licence":"CC BY 3.0","author":"Niagara","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Pithole_Stone_Arch_Bridge.jpg\" rel=\"noopener\">Niagara</a>, <a href=\"https://creativecommons.org/licenses/by/3.0\" rel=\"license noopener\">CC BY 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Pithole_Stone_Arch_Bridge.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71993965","wikipedia":"https://en.wikipedia.org/wiki/Pithole_Stone_Arch_Bridge","wikidata":"https://www.wikidata.org/wiki/Q7198946"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/venango-county/pithole-stone-arch-88000869/"}