Melvin Price Locks and Dam replaced Lock and Dam 26, which was demolished in 1990. The construction of the Melvin Price Locks and Dam constituted the first replacement of an original installation of the 9-Foot Channel Project.

The Melvin Price Locks and Dam is located approximately two miles downstream from the decommissioned Locks and Dam 26.

Melvin Price Locks and Dam was designed and constructed as a replacement for Locks and Dam No. 26 as part of the Mississippi River Nine-Foot Navigation Project. This locks and dam provide the portion of the continuous Mississippi Nine-Foot Navigation Project to Lock and Dam 25 on the Mississippi River, and LaGrange Lock and Dam on the Illinois River.

Placed in operation October 10, 1989, Melvin Price Locks and Dam is a 1,160-foot-long dam structure equipped with a 1200-foot lock chamber and a 600-foot lock auxiliary chamber, nine Tainter gates and an emergency spillway. 

Melvin Price Locks and Dam was built in three phases.  The first phase was the spillway and 6.5 tainter gate bays on the Missouri side.  The second phase was the 1200-foot lock chamber and the third phase was the 600-foot lock chamber and crow’s nest completed in 1994.

Serving as the largest of 29 lock facilities maintained by the U.S. Army Corps of Engineers on the Upper Mississippi River, Melvin Price Locks and Dam is a vital link in the inland waterway system. The St. Louis District maintains a 9-foot-deep navigation channel on the Upper Mississippi River and operates 5 locks and dams to support navigation.