{"nrhp_refnum":"95000540","name":"Muddy Creek Bridge, Maryland and Pennsylvania Railroad","other_names":[],"category":"structure","location":{"address":"Maryland and Pennsylvania RR tracks over Muddy Cr., E of Creek Ridge Rd., Peach Bottom and Lower Chanceford Townships","address_restricted":false,"city":"Sunnyburn","county":"York County","state":"PA","lat":39.760340350000035,"lon":-76.35105236699997,"geom_source":"nps_gis"},"listed_date":"1995-05-04","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["local"],"summary":{"what_it_is":"A single-span steel Pratt through-truss railroad bridge carrying the Maryland and Pennsylvania Railroad over Muddy Creek in Sunnyburn, York County, Pennsylvania. It rests on two stone abutments and is about forty yards long.","why_significant":"The nomination argues the bridge is one of the most significant engineering designs on the railroad's route and one of the few through-truss bridges in York County. It was built where the wide creek called for a stronger design than the girder bridges used on the line's smaller tributaries. It also illustrates alternative railroad bridge engineering of the late 19th and early 20th centuries.","narrative":"Sunnyburn, in York County, Pennsylvania, is the site of a steel Pratt through-truss bridge carrying the Maryland and Pennsylvania Railroad across Muddy Creek. Built about 1909 by the railroad company, the bridge replaced earlier trestle bridges along the line. Its roughly forty-yard span rests on two stone abutments and has eight vertical and twelve diagonal braces, with the diagonals in tension and the verticals in compression. The line linked the farms and merchants of southern York County to the Baltimore market. Because Muddy Creek is much wider than the streams the railroad crosses elsewhere, engineers chose a through-truss rather than the girder bridges common on the route. The structure is the only bridge on the line that crosses the creek, and it is regarded as one of the line's most significant engineering works. The bridge has been out of use since the railroad was abandoned in the 1970s, but it remains in good condition.","period_of_significance":"c. 1909 - 1942","architect_builder":null,"architectural_style":null,"criteria":["C"],"status_note":"No longer in use; the document states it remains in good condition with its integrity intact.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:36.080172-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/95000540.pdf"},"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994105","wikipedia":"https://en.wikipedia.org/wiki/Muddy_Creek_Bridge,_Maryland_and_Pennsylvania_Railroad","wikidata":"https://www.wikidata.org/wiki/Q6931652"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/york-county/muddy-creek-bridge-maryland-and-pennsylvania-railroad-95000540/"}