The
Army Corps of Engineers has studied the expansion of some locks on the
Upper Mississippi. Since at least 1999, the Corps has considered expanding 600 ft locks
20,
21,
22,
24, and
25 to 1,200 ft. ;Gallery Image:Upper Mississippi.png|The inland and intercoastal waterways, with the Upper Mississippi highlighted in red. Image:Upper Mississippi River Stairway of Water.png|Upper Mississippi River Stairway of Water. File:Upper_Mississippi_locks_expansion_study.jpeg|Upper Mississippi locks expansion study File:Lock and Dam 6 time lapse.webm|
Lock and Dam 6 time lapse ==See also==