Lock and Dam No. 24

39°22′36″N 90°54′30″W / 39.37667°N 90.90833°W / 39.37667; -90.90833Construction beganJuly 1936Opening dateMarch 12, 1940Operator(s) U.S. Army Corps of Engineers, St. Louis DistrictDam and spillwaysImpoundsUpper Mississippi RiverLength1,340 feet (408.4 m)ReservoirCreatesPool 24Total capacity125,363 acre⋅ft (0.154633 km³)Catchment area140,900 sq mi (365,000 km²) Location350 N. First St., Clarksville, MissouriArea102.7 acres (41.6 ha)Built1940MPSUpper Mississippi River 9-Foot Navigation Project MPSNRHP reference No.04000183^[1]Added to NRHPMarch 10, 2004

Lock and Dam No. 24 is a lock and dam located near Clarksville, Missouri around river mile 273.4 on the Upper Mississippi River. The main lock is 110 feet (33.5 m) wide and 600 feet (182.9 m) long with its bottom at an elevation of 430 feet. The auxiliary lock is not operational. Normal pool elevation behind the dam is 449 feet. The movable portion of the dam is 1,340 feet (408.4 m) long and consists of 15 submersible, elliptical, tainter gates. A 2,720 feet (829.1 m) submersible earthen dike extends from the movable dam to the Illinois shore.^[2] In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No. 24 Historic District, #04000183 covering 1,027 acres (4.2 km²), 3 buildings, 15 structures, 4 objects.

• List of locks and dams of the Upper Mississippi River
• Public Works Administration dams list

• Media related to Mississippi River Lock and Dam number 24 at Wikimedia Commons
• Lock and Dam No. 24 - U.S. Army Corps of Engineers
• Clarksville Visitor center, near the lock and dam with additional dimensions of the dam
• Lock 24
• Historic American Engineering Record documentation:
  • HAER No. MO-36, "Upper Mississippi River Nine-Foot Channel Project, Lock & Dam No. 24, Clarksville, Pike County, MO", 44 photos, 9 data pages, 3 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