XXX FISHES OF ILLINOIS 



lage of Bedford. It then curves to the southwest, passes through a 

 gap in the rocky ridge, which to the north and south constitutes the 

 divide between the Mississippi and the Illinois, and enters the Missis- 

 sippi opposite the town of Louisiana, Mo. The deflection to the west 

 is due to the ridge of Illinoisan drift which follows the east border of 

 the stream and prevents it from entering the Illinois valley. The 

 river has a length of about 50 miles, rising at an altitude of 850 feet, 

 but falling 100 feet in its first two miles, and below this averaging a 

 fall of nearly 7 feet to the mile until it enters the Mississippi flats. 

 The mouth is at an altitude of about 430 feet. 



CAHOKIA RIVER 



Cahokia River rises in southern Macoupin county and flows south 

 and west, emptying into the Mississippi near East St. Louis. It is 

 about 50 miles long, rising at an altitude of 640 feet, but falling 120 

 f< ( t in the first 6 miles. Below this it descends to 425 feet at Wanda, 

 the point at which it crosses the Mississippi bluffs and enters the bot- 

 tom-lands of that river. The mouth of the stream has an elevation 

 of about 400 feet. The banks above Wanda are steep and abrupt, 

 rising 100 feet or more on either side of the water. 



Illinois River System 



The Illinois and its branches drain an area of 29,013 square miles, 

 distributed among three states. Of this area, 24,726 square miles are 

 in Illinois, extending in a broad band, 250 miles long and averaging 

 100 miles in wi< 1th, i lirectly across the center of the state in anortheast- 

 southwest direction. From the upper extremity of this band are two 

 projections: one north into Wisconsin, covering 1,080 square miles in 

 that state; the other east into Indiana, covering 3,207 square miles 

 of its northern portion. This eastern projection forms the basin of 

 the Kankakee River, while the northern one includes the basins of 

 the Fox and Des Plaines rivers. It is the union of the drainage of 

 these two projections which may be considered as the origin of the 

 [llinois, this name being applied to the river from the point of junc- 

 tion of the Kankakee and the Des Plaines in eastern Grundy couni v, 

 Illinois. The Illinois flows westward for about 55 miles, turns 

 rather abruptly southwest a little north of Hennepin and follows 

 this direction until it empties into the Mississippi at the southern end 

 of Calhoun county. The river may readily be divided into two 

 parts: the upper Illinois, consisting of that portion of the river 

 above the turn at 1 [ennepin : and the lower Illinois, below this point. 



