Smithland Locks and Dam


Smithland Locks and Dam is located on the Ohio River at mile 918.5 below Pittsburgh, Pennsylvania and 62.5 miles upstream of the confluence of the Ohio and Mississippi rivers. The locks are on the Illinois side of the Ohio River accessible via the New Liberty Road reached from either Golconda or Brookport, Illinois.


The Smithland Locks and Dam was authorized on December 8, 1965, as a replacement for existing Locks and Dam 50 and 51, under authority of Section 6 of the Rivers and Harbors Act of March 3, 1909.


Smithland Locks’ construction started in 1971 and was placed in operation 1979. The dam construction started in 1974 and was completed in November 1980. The two Smithland Locks are each 110 feet wide and 1,200 feet long. This was the first structure of this size on the Ohio River and was then the world’s largest twin navigational locks system. The overall length of the river lock wall, including the guard walls, is approximately threequarters of a mile. Each miter gate leaf weighs 250 tons. The miter gates and valve machinery are hydraulically operated. Each lock chamber requires eight minutes for filling and nine minutes for emptying.

Locks and Dams

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Ohio River

Markland Locks and Dam
2760 US 42 West
Warsaw, KY 41095
(859) 567-7661

McAlpine Locks and Dam
805 North 27th Street
Louisville, KY 40212
(502) 776-6866

Cannelton Locks and Dam
5281 E. State Road 66
Cannelton, IN 47520
(812) 547-2962

Newburgh Locks and Dam
6877 State Road 66
Newburgh, IN 47630
(812) 853-8470

John T. Myers Locks and Dam
16501 Raben Road
Mt. Vernon, IN 47620
(812) 838-5836

Smithland Locks and Dam
1401 Smithland Dam Road
Brookport, IL 62910
(618) 564-2315

Olmsted Locks and Dam
567 New Dam Road
Olmsted, IL 62970
(618) 748-6400


Green River

Green River 1
5048 Dam and Lock Road
Reed, KY 42451
(270) 826-7360

Green River 2
695 W. 1st Street
Calhoun, KY 42327
(270) 273-3152

Lock Information

 River Lock  110’ x 1200’
 Land Lock  110’ x 1200’

Dam Information

Type Concrete fixed
weir with tainter gate
Length 2,954'
Upper pool 324'
Lower pool 302'
Number of gates 11
Height of gates 36'
Width of gates 110'