In 1891, Goethals was promoted to captain. He soon was placed in charge of the completion of the Muscle Shoals Canal along the Tennessee River near Florence, Alabama. This was his first independent command, and his responsibilities included the design and construction of the Riverton Lock at Colbert Shoals. His recommendation of a single lock with an unprecedented lift of twenty-six feet was initially opposed by his superiors in Washington, and he was forced to persuade the conservative army engineers of the merits of his design. The lock's successful construction set a world record for lock height. The success of the Riverton Lock inspired the eventual adoption of high-lift locks elsewhere, including those for the Panama Canal.