 In 1945 , the USACE began the Missouri River Bank Stabilization and Navigation Project , which would permanently increase the river 's navigation channel to a width of 300 feet ( 91 m ) and a depth of nine feet ( 2 @.@ 7 m ) . During work that continues to this day , the 735 @-@ mile ( 1 @,@ 183 km ) navigation channel from Sioux City to St. Louis has been controlled by building rock <unk> to direct the river 's flow and <unk> out sediments , sealing and cutting off meanders and side channels , and dredging the riverbed . However , the Missouri has often resisted the efforts of the USACE to control its depth . In 2006 , several U.S. Coast Guard boats ran aground in the Missouri River because the navigation channel had been severely <unk> . The USACE was blamed for failing to maintain the channel to the minimum depth . 
