506 THE ILLINOIS GLACIAL LOBE. 



small tract lying east of the moraine. As above noted, the Kankakee 

 formerly constituted the line of discharge for the St. Joseph River, now 

 tributary to Lake Michigan, and it is probable that it carried also a large 

 amount of glacial drainage from the Saginaw and Lake Michigan lobes (see 

 PI. XV). 



With the exception of the somewhat distinct watersheds of the Iroquois 

 and Yellow rivers, the Kankakee area constitutes a single great basin, 

 having only small tributaries leading directly from the i*im to the river or 

 marsh. The Kankakee marsh embraces probably l,00l) square miles, or 

 about one-fifth of the watershed. In addition to this, about 3,000 square 

 miles have very poor drainage. The best-drained portions are on the 

 Valparaiso moraine and the plains in Illinois between the Valparaiso and 

 Marseilles moraines. These, however, are poorly supplied with channels 

 for discharge, and much ditching and tile draining have been found necessary. 

 The head of the Kankakee marsh near South Bend, Indiana, stands about 

 140 feet, above Lake Michigan, or 720 feet above tide. From this point to 

 Momence, Illinois, a distance of 82 miles by direct line, there is a continuous 

 marsh which has a somewhat uniform descent of about 15 inches to the 

 mile, its altitude at Momence being 104 feet lower than at South Bend. 

 The windings of the stream are reported by Cooley to increase its length 

 to about 250 miles, and thus to reduce the fall to only 5 inches to the mile. 

 The amount of water above the junction with Yellow River is insufficient to 

 form a well-defined channel, but below that point there is quite a definite 

 open channel. The small tributaries are usually lost in the marsh before 

 reaching the main stream. The Kankakee Valley Drainage Company has 

 estimated that 625 square miles may be directly reclaimed and 1,000 

 square miles benefited by systematic ditching. 1 



At Momence occurs the first limestone outcrop in the bed of the river. 

 In the 14 miles below Momence to the junction with the Iroquois there is a 

 rock bed and a fall of 25 feet. In the 33£ miles from the mouth of the 

 Iroquois to the head of the Illinois the Kankakee falls 103 feet, or an 

 average of 3 feet to the mile. There are rapids near Altorf and at Wil- 

 mington, each of which have a descent of about 20 feet. The inner valley 

 is but little wider than the stream, and has a depth of only 15 feet at 

 Momence, 25 feet at Kankakee, and about 35 feet in western Kankakee and 



1 See official report to governor of Indiana, 1882. 



