Gateways to Commerce: The U.S. Army Corps of Engineers' 9-Foot Channel Project on the Upper Mississippi River

The Upper Mississippi River 9-Foot Channel is a unique engineering entity. No two lock and dam complexes on the Upper Mississippi are exactly the same. Each was shaped by its place in the technological development of the 9-Foot Channel Project. Each was also designed specifically for its location, reflecting the navigational needs and hydrological characteristics of that stretch of river. As noted by one Corps historian, the system was only as strong as its weakest link—all of the installations had to function as part of a system while, at the same time, accommodating local needs. [1]

Personnel at Lock and Dam No. 4, located at Alma, Wisconsin, c. 1936. (American Heritage Center, University of Wyoming)

The Upper Mississippi Valley Division designed the major elements of the 9-Foot Channel Project between 1929 and 1933. During these years, Lieutenant Colonel George Spalding headed the UMVD. William McAlpine was Head Engineer, assisted by Edwin Abbott and Lenvik Ylvisaker. In 1933, when the 9-Foot Channel Project was reshaped into a massive public employment program, the administration of the project was also reshaped. To achieve maximum employment, the Corps began working on all of the as-yet-unstarted lock and dam complexes simultaneously. So that the greatest number of tasks could be undertaken concurrently, Corps officials decentralized the project. As a result, the influence of the UMVD was greatly reduced after 1933. At the same time, the staff and activities of the St. Paul, Rock Island, and St. Louis Districts were greatly enlarged.

The UMVD, under the leadership of Spalding and McAlpine, developed prototypes for the locks and dams of the Upper Mississippi. However, many of the design and construction innovations associated with the 9-Foot Channel Project were also made by the district engineers. The districts conducted specialized testing that proved to be of great importance to the 9-Foot Channel Project. Engineers in the St. Paul, Rock Island, and St. Louis Districts frequently devised unprecedented solutions for problems presented by building a slack-water navigation system on the Upper Mississippi. New developments in one district frequently permitted, facilitated, or compelled improvements in another district.

On the following pages are outlines of the lock and dam installations on the Upper Mississippi River, as well as brief descriptions of the St. Paul, Rock Island, and St. Louis Districts. Although the Corps of Engineers did not build the locks and dams of the Upper Mississippi in numerical order, they are presented as such in this chapter. They are also presented under the districts that administered their construction.