92 THE ILLINOIS GLACIAL LOBE. 



banks, and it has the appearance of being a stream channel or bed rather 

 than a valley proper, the only flood plain being the bordering uplands. A 

 fine view of the valley may be obtained just west of Columbus. Before 

 reaching Winfield a channel branches off to the west from the main channel 

 and joins it again just south of Wyman. This channel has a breadth of 

 but one-eighth mile or less. It is more direct than the main channel, and 

 has about the same depth. 



A short distance east of Winfield the main channel is entered from 

 the east by the East Fork of Crooked Creek, and this stream meanders 

 through the broad bottom of the main channel westward to its junction 

 with the West Fork, and thence continues west and south to Skunk River 

 Vallev at Coppock. Another channel leads directly west from Winfield 

 past Wayne to Coppock, a distance of 15 miles. The combined width of 

 the two channels is but little greater than that of the portion of the channel 

 north from Winfield, the channel along Crooked Creek being about three- 

 fourths to 1 mile in width and the channel leading past Wayne one-fourth 

 mile. The lower portion of Crooked Creek nearly occupies the full width 

 of the north channel, but throughout the greater part of the course it is 

 bordered by a broad terrace-like, plain, several times the breadth of the 

 valley which it has excavated. The depth of about 25 to 35 feet continues, 

 as in the portion north from Winfield. 



The portion along Skunk River from Coppock to Rome, a distance of 

 10 miles, is so completely occupied by the valley of that river that only 

 occasional narrow remnants of the abandoned channel appear as terraces 

 on its borders, the average breadth of that part of Skunk River Valley 

 being fully 1 mile. The most extensive remnant of the abandoned channel 

 is found in the double oxbow made by the river north and west from the 

 village of Rome, which stands, where not broken down by subsequent 

 erosion, about 670 to 675 feet above tide. 



From Rome the abandoned valley continues southward along the 

 valley of Big Cedar Creek (reversed) and is preserved in terracelike rem- 

 nants on each border of the valley which stand 30 feet or more below the 

 level of the upland plain. The average breadth of the vallev being not 

 less than one-half mile the terrace remnants are narrow. From the bend of 

 the Big Cedar, 8 miles south of Rome, the old valley, as noted above, leads 

 southeastward across Lee County to the Mississippi Valley at Viele, 6 miles 

 below Fort Madison, gradually deepening from 30 feet at the north to 50 



