Lock and Dam No. 20

Lock and Dam No. 20 extends 2,369 feet across the Upper Mississippi River, featuring 40 tainter gates and 3 roller gates for water control.

The United States Army Corps of Engineers constructed this navigation structure in 1935 for 4.45 million dollars at the former location of Tully, Missouri.

The 839-acre historic district encompasses numerous engineering elements, including an Operations Building and two locktenders' houses, reflecting 1930s infrastructure development.

The lock chamber measures 110 feet in width and 600 feet in length, allowing vessels to navigate between different water levels on the Mississippi River.

The dam creates Pool 20, which holds 58,000 acre-feet of water and manages a catchment area of 134,300 square miles along the Mississippi River.

Location: Lima Township

Location: Canton Township

Architects: United States Army Corps of Engineers

Elevation above the sea: 148 m

Website: https://mvr.usace.army.mil/Missions/Navigation/Lock-and-Dam-Information/Lock-and-Dam-20

GPS coordinates: 40.14417,-91.51000

Latest update: March 8, 2025 12:31