GENERAL PHYSICAL FEATURES. 133 



Lakes and rivers.] 

 > 



tory iu the Union, being 5,637.53 square miles, without including any part 

 of lake Superior.* This averages one square mile of water to every fifteen 

 of land for the entire state. This unprecedented water supply leaves the 

 state by the valleys of seven different rivers, viz: the Mississippi, the St. 

 Louis and lake Superior, the Red river of the North, the Rainy river, the 

 Ues Moines river, the Rock river, and the Cedar river. 



The Mississippi river system. By far the largest and most important 

 of these drainage systems is that of the Mississippi. It is the only one that 

 crosses the entire state. It includes the most of the area of the great 

 water-shed formed by the morainic deposits in the central portions of the 

 state, its whole area being approximately 45,566 square miles. The upper 

 Mississippi drains the timbered regions, and the Minnesota the southern 

 prairie portions of Minnesota. It runs almost exclusively on the surface 

 of the drift to the falls ot St. Anthony, and from there till it leaves the 

 state, and even till it enters the gulf of Mexico, it runs in an old, rocky 

 valley excavated in pre-glacial times. All its tributaries, also, below the 

 falls of St. Anthony enter it through similar, deep-cut gorges. The other 

 tributaries of this river, however, are post-glacial, and have excavated their 

 valleys but little within the drift sheet. They rarely reveal the bed-rock. 

 As the area drained by the upper Mississippi, as well indeed as that of the 

 whole state, may be taken all together, as a great, but slightly roughened, 

 or undulating plain, the valleys exhibit great monotony in their topography 

 and other features. 



The system of the Red river of the North. The Red river of the North 

 rises in the same rolling region as the Mississippi, at a point about twelve 

 miles west of Itasca lake, at an elevation of 1600 feet above the ocean, and 

 leaves the state, after a circuitous route by the south, with an elevation of 

 767 feet. The entire area is heavily covered with northern drift, and after 

 leaving the rolling morainic regions of Becker and Otter Tail counties, the 

 river passes through the fertile "Red river valley," which in its flatness and 

 monotony, no less than its area, resembles the northern steppes of Russia 

 and Siberia, to which also it seems to have had an analogous origin. The 

 aggregate area of the state drained by this river is 15,107 square miles, and 



