where does the st. joe river start?
Lake Michigan
entailment
 The Missouri River is the longest river in North America . Rising in the Rocky Mountains of western Montana , the Missouri flows east and south for 2 @,@ 341 miles ( 3 @,@ 767 km ) before entering the Mississippi River north of St. Louis , Missouri . The river takes drainage from a sparsely populated , semi @-@ arid watershed of more than half a million square miles ( 1 @,@ 300 @,@ 000 km2 ) , which includes parts of ten U.S. states and two Canadian provinces . When combined with the lower Mississippi River , it forms the world 's fourth longest river system . 

entailment
 Originally created by plate tectonics about 35 million years ago and subsequently altered by volcanism and erosion , the river 's drainage basin was significantly modified by the Missoula Floods at the end of the most recent ice age . Humans began living in the watershed over 10 @,@ 000 years ago . There were once many tribal villages along the lower river and in the area around its mouth on the Columbia . Indigenous peoples lived throughout the upper reaches of the basin as well . 

contradiction
 The Missouri River officially starts at the confluence of the Jefferson and Madison in Missouri Headwaters State Park near Three Forks , Montana , and is joined by the Gallatin a mile ( 1 @.@ 6 km ) downstream . The Missouri then passes through Canyon Ferry Lake , a reservoir west of the Big Belt Mountains . Issuing from the mountains near Cascade , the river flows northeast to the city of Great Falls , where it drops over the Great Falls of the Missouri , a series of five substantial waterfalls . It then winds east through a scenic region of canyons and badlands known as the Missouri Breaks , receiving the Marias River from the west then widening into the Fort Peck Lake reservoir a few miles above the confluence with the Musselshell River . Farther on , the river passes through the Fort Peck Dam , and immediately downstream , the Milk River joins from the north . 

entailment
 Elevations in the watershed vary widely , ranging from just over 400 feet ( 120 m ) at the Missouri 's mouth to the 14 @,@ 293 @-@ foot ( 4 @,@ 357 m ) summit of Mount Lincoln in central Colorado . The river itself drops a total of 8 @,@ 626 feet ( 2 @,@ 629 m ) from Brower 's Spring , the farthest source . Although the plains of the watershed have extremely little local vertical relief , the land rises about 10 feet per mile ( 1 @.@ 9 m / km ) from east to west . The elevation is less than 500 feet ( 150 m ) at the eastern border of the watershed , but is over 3 @,@ 000 feet ( 910 m ) above sea level in many places at the base of the Rockies . 

contradiction
 The Missouri River is the largest and longest river in the state . Other major South Dakota rivers include the Cheyenne , James , Big Sioux , and White Rivers . Eastern South Dakota has many natural lakes , mostly created by periods of glaciation . Additionally , dams on the Missouri River create four large reservoirs : Lake Oahe , Lake Sharpe , Lake Francis Case , and Lewis and Clark Lake . 
