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. A 2,566 feet (782.1 m) submersible dike extends to the Illinois shore. A 5 miles (8.0 km) long dike is part of the facility extending upstream on the Missouri side of the river. The main lock is 110 feet (33.5 m) wide by 600 feet (182.9 m) long.^[2] In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No. 25 Historic District, #04000184 covering 3,164 acres (12.8 km²), 2 buildings, 7 structures, 2 objects.

• Public Works Administration dams list

• USGS Reach 2, Pool 25
• Historic American Engineering Record documentation:
  • HAER No. MO-37, "Upper Mississippi River Nine-Foot Channel Project, Lock & Dam No. 25, Cap au Gris, Lincoln County, MO", 93 photos, 9 data pages, 7 photo caption pages
  • HAER No. MO-50, "Upper Mississippi River Nine-Foot Channel Project, Lock & Dam Nos. 24-27, Clarksville, Pike County, MO", 125 data pages