THE TOPOGRAPHY AXD HYDROGRAPHY OF ILLINOIS Ixix 



leaving a bottom from 3 to 5 miles in w'dth between them and 

 the Cache. 



The headwaters of Cache River are in eastern Union county, 

 the river winding first southeast, then south-southwest, south, 

 and east, emptying finally into the Ohio River a few miles 

 below Mound City. It traverses a distance of about 73 miles, 

 beginning at an altitude of 500 feet. It falls 50 feet in a little 

 over 2 miles, 100 feet in the next 15 miles, and only 70 feet in 

 the remainder of its course. Near its head it has a definite 

 channel, but just west of the Union- Johnson county line it 

 enters its first cypress swamp. This, however, is very small, 

 and the bottom-lands again become higher and drier, averaging 

 about half a mile in width for the next nine miles. Then for a 

 distance of about 3 miles there is scarcely any bottom-land, 

 below which the river enters an extensive cypress swamp having 

 a width of 5 miles in some places. A few miles above Collins- 

 burg the bottom again becomes narrow and ledges of sandstone 

 form the bed of the stream, which here is clear and swift. Below 

 this point the water is nearly stagnant, brown in color, and full 

 of drifted logs. The lowlands average about three fourths of a 

 mile in width to near the mouth of Dutchman creek, where 

 they spread out to almost two miles. At the Massac county 

 line, Cache River enters the main swamp region which extends 

 across Pulaski county, and below these swamps the river winds 

 about through wide bottoms to its mouth. The backwater of 

 the Ohio reaches up Cache River hardly as far as Ullin, and 

 floods above this point are more immediately caused by the 

 headwaters of the stream when their discharge is impeded by 

 backwater. The country around the upper Cache is hilly and 

 precipitous, and so in times of freshets it pours immense quan- 

 tities of water into this lower flat, which then becomes a reservoir. 

 As the waters which the Cache carries come from the Missis- 

 sippian and cretaceous, they are somewhat different in mineral 

 characteristics from any of the rivers heretofore described. 



BIG BAY CREEK 



Big Bay creek drains 275 square miles in eastern Johnson 

 and western Pope counties an area very similar in character 

 to that drained by the Cache. The stream rises in northwestern 

 Pope county, flows southwest into Johnson county, takes there 

 a southeasterly direction, and empties into the Ohio near Bay 



