{"nrhp_refnum":"79001869","name":"Mill Road Bowstring Bridge","other_names":[],"category":"structure","location":{"address":"Mill Rd","address_restricted":false,"city":"Bladensburg","county":"Knox County","state":"OH","lat":40.27644934500006,"lon":-82.27254485999998,"geom_source":"nps_gis"},"listed_date":"1979-12-05","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"An iron bowstring arch-truss bridge spanning Wakatomika Creek on Mill Road (Township Road 184) near Bladensburg, Knox County, Ohio, built about 1876 by the Wrought Iron Bridge Co. of Canton.","why_significant":"The nomination argues it is a rare surviving metal bowstring arch-truss, a type that marks an important segment of engineering history. It was built by a leading bridge company using patented compression tubes from the Phoenix Iron Company. The decline of the former mill settlement left it among the few such bridges surviving in Ohio.","narrative":"Spanning Wakatomika Creek on a dirt road in hilly farmland near Bladensburg, this iron bowstring arch-truss bridge is about seventy-five feet long with a sixteen-foot roadway. Two hollow arched tubes, each made of four iron plates, carry the load and bear the Phoenix Iron Co. name and an 1862 patent date. The bridge rests on rock-faced sandstone piers and was built around 1876 by the Wrought Iron Bridge Company of Canton, a firm that became one of the nation's leading metal bridge fabricators. The bowstring arch-truss was first patented by Squire Whipple in 1841, and the type was later displaced by stronger box trusses, steel and reinforced concrete. It was listed because it is a rare survivor of that type in Ohio. The mill and settlement that once surrounded the crossing have faded, which helped preserve the bridge. It is now closed to traffic, with a deteriorated deck, but the structure remains unaltered.","period_of_significance":"c. 1876","architect_builder":"Wrought Iron Bridge Co., Canton","architectural_style":null,"criteria":[],"status_note":"Closed to vehicular traffic and in poor condition; much of the wood deck is missing or badly deteriorated and the iron frame is rusting, but the structure appears intact and unaltered.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:12.960135-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/79001869.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/79001869/f7b54622eb-800.webp","url_1600":"https://nationalhistoricalregister.com/media/79001869/f7b54622eb-1600.webp","licence":"Public domain","author":"Joseph Elliott","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Mill_Road_Bowstring_Bridge.jpg\" rel=\"noopener\">Joseph Elliott</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Mill_Road_Bowstring_Bridge.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71989535","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q122229602"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/knox-county/mill-road-bowstring-bridge-79001869/"}