{"nrhp_refnum":"78002175","name":"St. Clair Street Bridge","other_names":[],"category":"structure","location":{"address":"over Seven Mile Creek","address_restricted":false,"city":"Eaton","county":"Preble County","state":"OH","lat":39.739983497000026,"lon":-84.63851677499997,"geom_source":"nps_gis"},"listed_date":"1978-09-21","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["state"],"summary":{"what_it_is":"A 104-foot single-span Pratt metal through-truss bridge carrying St. Clair Street over Seven Mile Creek at the west edge of Eaton, Preble County, Ohio, built 1886-87 with limestone abutments.","why_significant":"The bridge is one of seven known Ohio metal through-truss bridges fabricated by the Columbia Bridge Works of Dayton. It is also the only known Columbia bridge using the more common lattice girder post design rather than the firm's distinctive paired u-channel intermediate posts, which makes it structurally unique.","narrative":"Carrying St. Clair Street over Seven Mile Creek at the west edge of Eaton, this 104-foot Pratt metal through-truss bridge has a single span of six panels and a 16-foot width. Its batter posts carry cannonball finials and a date of 1887, and a cast metal name plate bears the fabricator's name. The limestone abutments, built in 1886 by Adam and John Trunk, carry blocks cut with the county engineer's name and the masonry contractors' names. A flood earlier in 1886 destroyed many bridges across Preble County, and this one replaced a washed-out metal bridge farther upstream. It was fabricated by the Columbia Bridge Works of Dayton, one of seven known Ohio bridges from that firm. Six of them use a distinctive intermediate post of parallel u-channel beams, while this one uses lattice girder posts, making it the only known example of that type. The county engineer has expressed interest in keeping it, and its sidestreet location was seen as favorable for preservation.","period_of_significance":"1886-87","architect_builder":"Columbia Bridge Works; abutments by Adam and John Trunk","architectural_style":null,"criteria":[],"status_note":"Posted for a three ton limit; the bridge and abutments are still structurally sound according to the county engineer. Owned by the Preble County Commissioners.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:12.390147-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/78002175.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/78002175/0346bbca65-800.webp","url_1600":"https://nationalhistoricalregister.com/media/78002175/0346bbca65-1600.webp","licence":"Public domain","author":"Nyttend","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:St._Clair_Street_Bridge,_southwestern_angle.jpg\" rel=\"noopener\">Nyttend</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:St._Clair_Street_Bridge,_southwestern_angle.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71991061","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q113968612"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/preble-county/st-clair-street-bridge-78002175/"}