From the record
“Lock and Dam No. 25 is a lock and dam located near Winfield, Missouri, on the Upper Mississippi River around river mile 241.4. The movable portion of the dam is 1,296 feet (395.0 m) long and consists of three roller gates and 14 tainter gates.”
Wikipedia article Lock and Dam No. 25, CC BY-SA 4.0.
One of 5 National Register listings published here for Lincoln County · listed in 2004 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service