36 ILLINOIS STATE ACADEMY OF SCIENCE 



THE GEOGRAPHY OF THE OZARKS 



Prof. Frank H. Colyer, Southern Illinois 

 State Normal University. 



location and extent. 



The Ozarks, or the Ozark Ridge, is the name commonly 

 applied to the rugged highland that extends entirely across 

 southern Illinois from the Mississippi to the Ohio river. 

 It is really a spur, or an eastern extension of the Ozarks of 

 Missouri. This Illinois spur of the Ozarks is located chiefly 

 in the counties of Union, Johnson, Pope and Hardin, but it 

 also extends into the southern parts of Jackson, William- 

 son, Saline and Gallatin counties. 



The crest of the Ozarks is near the northern boundary of 

 Union, Johnson, Pope and Hardin counties. In Hardin 

 county the crest of the Ozarks is almost exactly on the 

 northern boundary line, but in the case of the other counties 

 the crest is several miles farther south. 



The Ozarks extend entirely across southern Illinois and 

 have a total length of 75 miles. While the width of the 

 Ozarks is by no means uniform, still its average is not far 

 from 25 miles. 



SURFACE. 



From the standpoint of altitude above mean sea level, 

 the so called "mounds" of Jo Davies county is the highest 

 part of Illinois. The highest hill in this region has an ele- 

 vation of 1257 feet, which is nearly 200 feet higher than 

 the highest part of the Ozarks. 



So far as now known, the highest hill in the Ozarks is 

 William's Hill in the northeastern part of Pope county. 

 This hill has an elevation of 1065 feet above mean sea level. 

 Bald Knob in Union county is, however, only 40 feet lower, 

 with an altitude of 1025 feet. There are a number of hills 

 in the crest of the Ozarks that have an altitude from 900 to 

 1000 feet.i 



1. Weller and Butts: Extract from Bull. No. 41, III. State Geological Survey, 

 1920, pp. 10. 



