THE OHIO VALLEY IN SOUTHERN INDIANA 



259 



widens until at Midway it is about four miles and at Lake P. O. 

 five, at which width it continues until it enters the second divi- 

 sion of the plain region, the River Plain of the present Ohio. 

 The average width of the River Plain is between four and 



Map or coast line: during the Lafayette: 



ACCORD IN6 TO Mc.GeE , SHOWING ALSO SUPPOSED 

 EXTENSION UP THE OhIO VALLEY 



{five miles. That portion which lies in Indiana is very irregular 

 on account of the meandering course of the river. It includes 

 .all land locally termed the river bottoms. Three and a half 

 miles below Enterprise, River Plain merges into Pigeon Plain. 



The third portion of the plain enters, or rather leaves, the 

 River Plain between Grandview and Rockport (Fig. 1), its 

 southern portion including part of the town of Rockport. It is 

 here three miles wide, but soon narrows down to two miles. It 

 extends westward three miles, where it turns abruptly north- 

 ward, and there narrows to about one mile. After going three 

 miles in this direction it turns westward again, and enters Pigeon 

 Plain two miles east of Lake P. O. The narrow part of this 

 plain was occupied by a shallow pond of water when this country 



