La Grange Lock and Dam

{{for|the dam in California|La Grange Dam}}

{{Use American English|date=January 2025}}

{{Use mdy dates|date=August 2023}}

{{Infobox NRHP

| name = LaGrange Lock and Dam Historic District

| nrhp_type = hd

| nocat = yes

| image = La Grange Lock and Dam Aerial View.jpg

| caption = Aerial view of the dam

| nearest_city = Versailles, Illinois

| coordinates = {{coord|39|56|27|N|90|32|02|W|display=inline,title}}

| locmapin = Illinois#USA

| built = {{Start date|1939}}

| added = March 10, 2004

| area = {{convert|17.6|acre}}

| mpsub = Illinois Waterway Navigation System Facilities MPS

| refnum = 04000170{{NRISref|version=2010a}}

}}

LaGrange Lock and Dam is a lock and dam complex on the Illinois River at Versailles, Illinois. The structure includes a {{convert|1066|ft}} dam and a {{convert|110|by|600|ft}} lock. The U.S. Army Corps of Engineers built the complex from 1936 to 1939; A.F. Griffin designed the lock and dam, while Paul Le Gromwell designed the control station. The lock and dam, as well as a similar lock and dam near Peoria, were needed when the authorized channel depth was raised to nine foot. The Peoria and LaGrange locks replaced older locks on the lower Illinois River. The lock uses Chanoine wicket gates, which allow for navigation on the river, rather than the Tainter gates seen elsewhere on the river.{{cite web|url=http://www.mvr.usace.army.mil/Portals/48/docs/CC/FactSheets/IL/LaGrange_LockandDam.pdf|title=LaGrange Lock & Dam|publisher=U.S. Army Corps of Engineers|accessdate=January 4, 2014|archive-url=https://web.archive.org/web/20140106040357/http://www.mvr.usace.army.mil/Portals/48/docs/CC/FactSheets/IL/LaGrange_LockandDam.pdf|archive-date=January 6, 2014|url-status=dead}}{{cite web|url=http://lcweb2.loc.gov/pnp/habshaer/il/il0900/il0921/data/il0921data.pdf|title=Illinois Waterway, La Grange Lock and Dam|publisher=Historic American Engineering Record|accessdate=January 4, 2014}}

The structure was added to the National Register of Historic Places on March 10, 2004.