Lock and Dam No. 12

42°15′41.08″N 90°25′12.47″W / 42.2614111°N 90.4201306°W / 42.2614111; -90.4201306Construction began1934-1939Opening dateMay 13, 1939Operator(s) U.S. Army Corps of Engineers, Rock Island DistrictDam and spillwaysImpoundsUpper Mississippi RiverLength8,369 feet (2,550.9 m)ReservoirCreatesPool 12Total capacity92,000 acre⋅ft (0.113 km³)Catchment area82,400 sq mi (213,000 km²) Location401 N. Riverview St.,
Bellevue, IowaArea101.7 acres (41.2 ha)Built1939ArchitectEdwin E. AbbotArchitectural stylelock and damMPSUpper Mississippi River 9-Foot Navigation Project MPSNRHP reference No.04000172^[1]Added to NRHPMarch 10, 2004

Lock and Dam No. 12 is a lock and dam located on the Upper Mississippi River at Bellevue, Iowa, United States. The movable portion of the dam starts at the locks adjacent to the Iowa shore and is 849 feet (258.8 m) long, consisting of seven tainter gates and three roller gates. It connects to a 200-foot (61.0 m) storage yard and continues toward the Illinois shore with a 2,750-foot (838.2 m) non-submersible dike, a 1,200-foot (365.8 m) submersible dike and a 3,130-foot (954.0 m) non-submersible dike. The non-submersible sections are separated from the submersible section with two 120-foot (36.6 m) transitional dikes. The main lock is 110 feet (33.5 m) wide by 600 feet (182.9 m) long. There is also an incomplete auxiliary lock.^[2] In 2004, the facility was listed in the National Register of Historic Places as Lock and Dam No. 12 Historic District, #04000172 covering 1,017 acres (4.1 km²), 1 building, 3 structures, and 4 objects.

• Savanna Army Depot, adjoining the facility on the Illinois side
• Public Works Administration dams list
• Upper Mississippi River National Wildlife and Fish Refuge

• Lock and Dam No. 12 - U.S. Army Corps of Engineers
• USGS Pool 12
• Historic American Engineering Record (HAER) No. IA-24, "Mississippi River 9-Foot Channel Project, Lock & Dam No. 12, Upper Mississippi River, Bellevue, Jackson County, IA", 23 photos, 15 data pages, 2 photo caption pages