Lock and Dam No. 26 was a lock and dam located near Alton, Illinois on the Upper Mississippi River around river mile 202.5.
Opened in 1938, its largest lock was 600 feet long. It was demolished in 1990 and replaced by the Melvin Price Locks and Dam, which is also known as Lock and Dam number 26.
On December 29, 1933, John Griffiths and Son Company of Chicago, Illinois, won the contact with a bid of $3,269,565.00, the lowest of five bids received on construction of the locks. Work officially started on January 13, 1934. Due to adverse river conditions, John Griffiths and Son Company gave up the contract in April 1936 with about a third of the work completed.
Engineering Construction Corporation, formed by Spencer, White and Prentis, George A. Fuller Company, and Turner Construction Company, all of New York City, bid $1,200,000 to complete the locks. This company also won with a bid of $4,856,716.80 to construct the dam. The contract was awarded on May 14, 1935 and work officially began on June 15, 1935.
"The twin locks, as designed, comprise a main lock basin long by wide, with 45-foot gates, and an auxiliary look basin long wide with 27-foot gates upstream. This lock width is standard in all locks being constructed in this series, and is the same as that of the Panama Canal Locks." Page 19.