THE TOPOGRAPHY AND HYDROGRAPHY OF ILLINOIS Ixi 



than in its lower and upper parts. It extends, on the west, to the 

 watershed of the Kaskaskia and on the east to the Embarras and 

 Bonpas watersheds. The entire basin Hes in the IlHnoisan drift, and 

 is made up of rolling prairies lying between the broad belts of wood- 

 land which skirt the streams. The difference in level between the 

 creek bottoms and the adjacent highlands does not usually exceed 

 50 to 75 or 100 feet. 



The river rises in southwestern Coles county, and flows south 

 through Shelby and Effingham coimties. In northern Clay county 

 it turns southeast for about 50 miles, and then flows alternately 

 southw^est and southeast until it empties into the Wabash at the 

 boundary line between Gallatin and White counties, eight miles, in a 

 direct line, from the junction of the Wabash with the Ohio River. 

 The length of the river is about 180 miles. Its source is in the Shel- 

 by ville moraine at an elevation of 740 feet, but it descends within 4 

 miles to 700 feet, to 650 feet in the next 2^ miles, and to 600 feet 12 

 miles below. Another descent of 100 feet is made in the following 

 31 miles, while at a point 42 miles below this the 400 feet contour- 

 line is crossed. The mouth of the stream, 104 miles distant, lies 323 

 feet above tide. Thus the total descent of the river is 317 feet, giv- 

 ing an average fall of about 1 . 7 feet per mile. 



In the first 40 to 50 miles the main stream is largely independent 

 of preglacial lines, and there is consequently little valley. The re- 

 mainder of its course, however, is determined by a broad preglacial 

 valley except for a short distance below Carmi, where it cuts across 

 a projecting spur of hills leading in from the west. This valley, like 

 others in this region, has been filled in its lower course with drift and 

 alluvium to a level perhaps 100 feet above the rock bottom (Lev- 

 erett) . It is from an eighth to a fourth of a mile wide in Effingham 

 county, but below, reaches a width of one to three miles. At times 

 the river is bordered locally by precipitous bluffs 40 to 50 or even 100 

 feet in height, while at other points there is a gradually sloping sur- 

 face from the bottoms up to the level of the adjacent prairie. The 

 river-bottoms are a rich, sandy loam, but are valued little for agri- 

 culture on account of the overflow to w^hich they are subject during 

 the annual spring freshets. They are, however, valued for the heavy 

 timber which covers them. 



The most important tributary of the Little Wabash is Skillet 

 Fork which enters from the west near Carmi. The length of this 

 stream is about 65 miles, not including the windings of its course, 

 and it has a watershed of nearly 1,000 square miles. It rises in 

 northeast Marion county and flows south and then southeast. Its 



