 The Upper Missouri River is north of Gavins Point Dam the last hydroelectric dam of 15 on the river and it 's just upstream from Sioux City , Iowa . The lower Missouri River is the 840 river miles until it meets the Mississippi just above St. Louis . The Lower Missouri River has no Hydroelectric or Lock and dams but it has a plethora of Wing dams that enable barge traffic by directing the flow of the river into a 200 foot wide , 12 foot deep channel . These wing dams have been put in place and maintained by the U.S. Army corps of engineers , and there currently are no plans to construct any Lock and dams to replace these wing dams on the Missouri River . 
 The Upper Missouri River <a href='drop_aux' title='1'><mark>is</mark></a>north of Gavins Point Dam the last hydroelectric dam of 15 on the river and it 's just upstream from Sioux City , Iowa . The lower Missouri River <a href='drop_aux' title='2'><mark>is</mark></a>the 840 river miles until it <a href='uninflect' title='3'><mark>meets</mark></a> the Mississippi just above St. Louis . The Lower Missouri River <a href='got' title='4'><mark>has</mark></a> no Hydroelectric or Lock and dams but it <a href='got' title='5'><mark>has</mark></a> a plethora of Wing dams <a href='null_relcl' title='6'><mark>that</mark></a>enable barge traffic by directing the flow of the river into a 200 foot wide , 12 foot deep channel . These wing dams <a href='been_done' title='7'><mark>have</mark></a> been put in place and maintained by the U.S. Army corps of engineers , and <a href='dey_it' title='8'><mark>there</mark></a> currently are no plans to construct any Lock and dams to replace these wing dams on the Missouri River . 
The Upper Missouri River north of Gavins Point Dam da last hydroelectric dam of 15 on the river and it 's just upstream from Sioux City , Iowa . Tdalower Missouri River thda40 river miles until it meet the Mississippi jus above St. Louis . Thedawer Missouri River got no Hydroelectric or Lock and dams but it got a plethora of Wing dams enable barge traffic by directing the daw of the river into a 200 foot wide , 12 foot deep channel . These wing dams done been put in place and maintained by the Uda Army corps of engineers , and it currently ain't no plans to construct any Lock and dams to replace these wing dams on the Midauri River .