185 



descent of about fiA'e feet ; here the stream has cut oft" an old oxbow and 

 is cutting down the rocli in the ridge encircled by the oxbow. 



The Patolca is a sluggish stream flowing along to the south of east 

 fork of White River for a distance of about 100 miles, with a very nar- 

 row drainage basin, nowhere exceeding twenty miles in width. The river 

 rises in the Huron Sandstone of southern Orange County, thus having 

 its source in the driftless area, but in the vicinity of Jasiier, Dubois 

 County, it conies in contact with the drift. The present drainage system 

 is made up of three small drainage systems which were fonuerly distinct 

 and the waters of which flowed to the northwestward to west and east 

 forks of White River. "The upper system embraced the portion above 

 Jasper, the old divide being at the northeast border of that village. The 

 middle system embraced the portion between Jasper and Velpen and the 

 lower part from Velpen down to the vicinity of Princeton. The old drain- 

 age way there turned north to White River near Hazelton, but the pres- 

 sent stream continues westward across a rock pass into the Wabash." — 

 Leverett. 



These streams which had then a northwestern discharge have been 

 turned westward, just outside the glacial boundary to form the present 

 Patoka River. 



The Wahash River has a large drainage area within the State. The 

 river rises in the western part of Ohio, flows across central Indiana then 

 turns south and from a point a few miles below Terre Haute forms the 

 Indiana-Illinois boundary to its junction with the Ohio. The main 

 .stream lies entirely within the glaciated area and practically all the 

 waters from the system come from the drift surface. The river enters 

 a preglacial valley just north of Lafayette, and after following this valley 

 for a few miles, turns southwestward across a rock point, while the pre- 

 glacial valley takes a longer route to the west and south, joining the 

 river at the bend near Covington. From this \yom\. southwest the river 

 follows the preglacial valley to the Ohio. Above Terre Haute the pres- 

 ent stream has cut out only a part of the old valley, while to the south 

 the river bottoms extend from bluff to bluff of the old valley. At Ten-e 

 Haute the valley is five miles wide, to the north from 2-4 miles, and 

 increases to the south to about fifteen miles near the mouth of the river. 

 In the upper part of its course at Huntington the river enters the old 

 outlet of glacial Lake Manmee. The old valley here is several times 



