Corps of Engineers opens its doors at Lock and Dam 4 for an open house,
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, , Press Operations, {authorlink}, https://www.mvp.usace.army.mil/Media/News-Releases/Article/3451348/corps-of-engineers-opens-its-doors-at-lock-and-dam-4-for-an-open-house/, https://www.mvp.usace.army.mil/DesktopModules/ArticleCS/RSS.ashx?ContentType=9&Site=465&isdashboardselected=0&max=20, St. Paul District News Releases,
, , U.S. Army Corps of Engineers – St. Paul, 1919, July 7, 2023, 12:56 pm