{"nrhp_refnum":"04000165","name":"Marseilles Lock and Dam Historic District","other_names":["Lock and Dam 5"],"category":"district","location":{"address":"1 Hawk Dr.","address_restricted":false,"city":"Marseilles","county":"LaSalle County","state":"IL","lat":41.32560386050005,"lon":-88.72146281744494,"geom_source":"nps_gis"},"listed_date":"2004-03-10","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Maritime History","Engineering"],"significance_levels":["national"],"summary":{"what_it_is":"A navigation lock and dam complex on the Illinois River at Marseilles, La Salle County, Illinois, with a 2.5-mile canal, a control station and a dam boiler house. The canal was built 1920-1925, and the lock and dam were completed in 1933.","why_significant":"The district is significant under Criterion A for its role in the maritime, transportation and industrial history of the Illinois Waterway. It is significant under Criterion C as a good representative example of Army Corps of Engineers-approved lock and dam construction of its period. It retains a high degree of integrity despite replaced equipment and surfaces.","narrative":"Marseilles Lock and Dam is a working navigation facility on the Illinois River in La Salle County. Its dam sits at one end of a 2.5-mile canal dug between 1920 and 1925 to bypass the Grand Rapids, and the lock sits at the downstream end. The lock, which lifts boats 25 feet, opened in 1933 with a 110 by 600 foot chamber, and Walter Mickle Smith was chief design engineer for the waterway project. The dam has three sections, including a main concrete pier dam with eight Tainter gates. Two brick buildings also contribute: a control station with a ceramic tile roof and gabled ends, and a dam boiler house once used to thaw gates. The district was listed for its part in the Illinois Waterway, which let commercial barges travel between Chicago and the Mississippi River, and as a representative Army Corps of Engineers lock and dam. Later changes, including a 1986 replacement control station and a rebuilt dam, have not erased its original character.","period_of_significance":"1920-1951","architect_builder":"Smith, Walter Mickle","architectural_style":"Other: lock and dam; No style: control station","criteria":["A","C"],"status_note":"Still an operating lock and dam facility; the original control station is now used for storage and houses the facility's power source, while a 1986 replacement control station operates the dam remotely.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:37.40104-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/7/8913/28891307/content/electronic-records/rg-079/NPS_IL/04000165.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/04000165/6add08ad23-800.webp","url_1600":"https://nationalhistoricalregister.com/media/04000165/6add08ad23-1600.webp","licence":"Public domain","author":"Government employee","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:MarseilleLocksACE.png\" rel=\"noopener\">Government employee</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:MarseilleLocksACE.png"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/28891307","wikipedia":"https://en.wikipedia.org/wiki/Marseilles_Lock_and_Dam","wikidata":"https://www.wikidata.org/wiki/Q6773267"},"indexable":true,"url":"https://nationalhistoricalregister.com/illinois/lasalle-county/marseilles-lock-and-dam-historic-district-04000165/"}