Images of Melvin Price Locks and Dam, Mississippi River Mile 200.5, Alton, IL.

Melvin Price Locks and Dam is a modern infrastructure project on the Mississippi River at Mile Marker 200.5. It is located approximately 20 miles above St. Louis, MO, and appr. 3 miles south of the Clark Superbridge (carrying U.S. Route 67) which spans the Upper Mississippi River between Alton, Illinois and West Alton, Missouri. In 2017, appr. 63 million tons of cargo passed through the locks, with 36 million tons being "Food and Farm Products " and 11 million tons of "Chemicals and Related Products", some 60,000 barges in both directions. It takes about 45 min to cross the locks.


The locks was put into operation in 1989, replacing the Locks and Dam 26, which were positioned two miles upstream of the current structure. The modern dam creates a 40.6-mile-long pool of 31,000 acres. The complex has twin locks, with the main lock being 110 by 1,200 feet and the auxiliary lock being 100 feet by 600 feet. The locks are U-shaped and supported on steel H-piles. The maximum lift is 24 feet. The movable dam has nine, open-frame, non-submersible Tainter gates, each 42 feet high by 110 feet long. Individual, electrically operated, cable hoists are housed in pier-top operating houses. The 1,160-foot-long movable dam is supported by steel H-piles driven into bedrock.


Melvin Price Locks and Dam (northbound view). Credit: Karatzas Images


History and Background Information


The lock was put into operation on October 10, 1989. The complex is also known as Locks and Dam 26R and constitutes the first replacement of an original installation of the 9-Foot Channel Project. The original lock and dam (Locks and Dam 26) was built in 1938, and the basic components of the new complex are similar to those of the old one with the most striking difference being the immense size of the new structure, which dwarfs the older installations.


The Upper Mississippi River (UMR) is defined as the stretch of the river from St. Paul, Minnesota, to the river’s confluence with the Missouri River. In the late 19th and early 20th centuries, this stretch of the Mississippi River was unreliable. During common periods of low water, the Upper Mississippi River had a shallow and swift current, rock ledges, small waterfalls, uncharted shoals and sandbars. These hazards made the river too treacherous to navigate safely.