{"nrhp_refnum":"03000353","name":"Lyndon Bridge","other_names":[],"category":"structure","location":{"address":"S end of 6th Ave. W","address_restricted":false,"city":"Lyndon","county":"Whiteside County","state":"IL","lat":41.711314635000065,"lon":-89.92434032999995,"geom_source":"nps_gis"},"listed_date":"2003-05-09","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A four-span steel through truss bridge carrying the south end of 6th Avenue West across the Rock River at Lyndon, Whiteside County, Illinois. Three Parker truss spans were built in 1894 and a Pratt truss span was added in 1912.","why_significant":"The bridge is significant under Criterion C for engineering as a good local example of the Parker Pratt through truss type with an added approach span. It is the only metal through truss bridge left on public roads in Whiteside County. It also reflects the shift from pin-connected to riveted construction.","narrative":"Lyndon Bridge spans the Rock River at the south end of 6th Avenue West in Lyndon, Illinois. Three 200-foot Parker through truss spans were built in 1894 to a design by engineer R.S. Riser, with Keefers & Wyncoop as builders. The total cost was $19,606.25, shared by the village and the county. In 1912 the county added a 100-foot riveted Pratt span to better cross the flood plain. Before the bridge, travelers south of the village had to use a ferry. The bridge is the only through truss bridge remaining on public roads in Whiteside County. It was closed to vehicles in 1980 and faced demolition in the 1990s. A local \"Save the Bridge\" campaign led to village ownership in 1998. The north abutment has been rebuilt, stringers replaced, and deck planks renewed as funds allow. It is now open to pedestrians and cyclists. Its significance rests on its engineering as a local example of both truss types.","period_of_significance":"1894-1912","architect_builder":"Riser, R.S., Engineer/Keefers & Wyncoop, Builders","architectural_style":"Other: Parker Pratt through truss bridge","criteria":["C"],"status_note":"Closed to motor vehicles in 1980 and later saved by a local campaign; the Village of Lyndon gained title in 1998. It has been inspected and deemed safe for pedestrian and bicycle use, with repairs ongoing.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:37.536821-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/99/8942/28894299/content/electronic-records/rg-079/NPS_IL/03000353.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/03000353/9b6b9905c5-800.webp","url_1600":"https://nationalhistoricalregister.com/media/03000353/9b6b9905c5-1600.webp","licence":"CC BY 2.5","author":"IvoShandor","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Lyndon_Il_Lyndon_Bridge1.jpg\" rel=\"noopener\">IvoShandor</a>, <a href=\"https://creativecommons.org/licenses/by/2.5\" rel=\"license noopener\">CC BY 2.5</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Lyndon_Il_Lyndon_Bridge1.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28894299","wikipedia":"https://en.wikipedia.org/wiki/Lyndon_Bridge","wikidata":"https://www.wikidata.org/wiki/Q6708721"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/whiteside-county/lyndon-bridge-03000353/"}