 The Missouri 's nickname , the " Big Muddy " , was inspired by its enormous loads of sediment or silt – some of the largest of any North American river . In its pre @-@ development state , the river transported some 175 to 320 million short tons ( 159 to 290 Mt ) per year . The construction of dams and levees has drastically reduced this to 20 to 25 million short tons ( 18 to 23 Mt ) in the present day . Much of this sediment is derived from the river 's floodplain , also called the meander belt ; every time the river changed course , it would erode tons of soil and rocks from its banks . However , damming and channeling the river has kept it from reaching its natural sediment sources along most of its course . Reservoirs along the Missouri trap roughly 36 @.@ 4 million short tons ( 33 @.@ 0 Mt ) of sediment each year . Despite this , the river still transports more than half the total silt that empties into the Gulf of Mexico ; the Mississippi River Delta , formed by sediment deposits at the mouth of the Mississippi , constitutes a majority of sediments carried by the Missouri . 
 The Missouri <a href='null_genetive' title='1'><mark>'s</mark></a>nickname , the " Big Muddy " , was inspired by its enormous loads of sediment or silt – some of the largest of any North American river . In its pre @-@ development state , the river transported some 175 to 320 million short tons ( 159 to 290 Mt ) per year . The construction of dams and levees <a href='been_done' title='2'><mark>has</mark></a> drastically reduced this to 20 to 25 million short tons ( 18 to 23 Mt ) in the present day . Much of this sediment is derived from the river <a href='null_genetive' title='3'><mark>'s</mark></a>floodplain , also called the meander belt ; every time the river changed course , it would erode tons of soil and rocks from its banks . However , damming and channeling the river <a href='been_done' title='4'><mark>has</mark></a> kept it from reaching its natural sediment sources along most of its course . Reservoirs along the Missouri trap roughly 36 @.@ 4 million short tons ( 33 @.@ 0 Mt ) of sediment each year . Despite this , the river still <a href='uninflect' title='5'><mark>transports</mark></a> more than half the total silt <a href='null_relcl' title='6'><mark>that</mark></a>empties into the Gulf of Mexico ; the Mississippi River Delta , formed by sediment deposits at the mouth of the Mississippi , <a href='uninflect' title='7'><mark>constitutes</mark></a> a majority of sediments carried by the Missouri . 
The Missouri  nickname , the " bigg Muddy " , was inspired by its enormous loads of sediment or silt – some of da largest of any North American river . In its pre @-@ development state , the river transported sum 175 to 320 million short tons ( 159 to 290 Mt ) per year . The construction of dams and levees done drastically reduced this to 20 to 25 million short tons ( 18 to 23 Mt ) in tdapresent day . Much of dis sediment is derived from thdaiver  floodplain , also called the meander belt ; every time the river changed course , it would erode tons of soil and rocks from its banks . However , damming and channeling the river done kept it from reachin its natural sediment sources along most of its course . Reservoirs along the Missouri trap roughly 36 @.@ 4 million short tons ( 33 @.@ 0 Mt ) of sediment each year . Despite tdis, the river still transport more den half the total silt empties into the Gulf of Mexico ; the Mississippi River Delta , formed by sediment deposits at thedauth of the dasissippi , constitute a majority of sediments carried by the Missouri .