THE TOPOGRAPHY AND HYDROGRAPHY OF ILLINOIS XXXlll 



It is about 50 miles in length, and drains about 366 square miles of 

 intermorainic country. It is a swiftly moving stream, the last 1 1 

 miles of its course having a fall of 80 feet. Its banks are generally 

 low and rolling. 



KANKAKEE RIVER 



Kankakee River rises in a large marsh about three miles south- 

 west of South Bend, St. Joseph county, Ind. It flows in a south- 

 westerly direction to the southern boundary line of La Porte county, 

 and then more westerly, crossing the Indiana-Illinois state-line in 

 southern Lake county, Indiana. It then flows a little south of west 

 to within a few miles of Kankakee, where it receives the Iroquois 

 from the south. Thence it proceeds almost due northwest to near 

 the northeast corner of Grundy county, where it unites with the Des 

 Plaines to form the Illinois. 



The Kankakee is about 140 miles long; 85 miles lying in Indiana. 

 Its drainage basin covers about 5,300 square miles, of which 3,200 

 square miles are in Indiana. This basin has its northern limits in the 

 Valparaiso morainic system, and all of the important northern tribu- 

 taries find their sources in the same system. Its southern limits, in 

 the portion below the mouth of the Iroquois, are found in the Mar- 

 seilles moraine. The Iroquois rises in a somewhat distinct area, 

 draining basins south of the Iroquois and Marseilles moraines and 

 passing through a gap in the latter moraine to enter the Kankakee. 

 The eastern limits of the Kankakee basin are mainly in the Maxin- 

 kuckee moraine of the Saginaw lobe. 



Probably the whole of the Kankakee basin was formerly an old 

 lake, called now by geologists Lake Kankakee, and, at the same 

 time that the old "Chicago outlet" was full, it may have been a line 

 of discharge for the St. Joseph River, now a tributary to Lake Michi- 

 gan, carrying also a large amount of glacial drainage from the Sagi- 

 naw and Lake Michigan lobes. 



The basin of the Kankakee is generally level, but near the state- 

 line, at Momence, occurs the first limestone outcrop in the bed of the 

 river. This ledge or arch has so prevented the wearing down of 

 the bed that a very large part of the drainage area in Indiana is one 

 vast swamp. From its source to the state-line there is a direct dis- 

 tance of only 75 miles, but within this distance the stream makes 

 2,000 bends and flows a total length of 240 miles. The difference 

 in level between its source and the state-line is but 97.3 feet, show- 

 ing a fall of but 1.3 feet to the mile. (Indiana Geological Survey.) 

 The winding of the river reduces the fall to only 5 inches to the mile. 



(c) 



