CHAPTER LXXI. 
REPORT ON THE GEOLOGY OF BUTLER COUNTY. 
BY EDWARD ORTON. 
BOUNDARIES AND TOPOGRAPHY. 
Butler county is bounded on the north by Preble and Montgomery 
counties, on the east by Warren, and on the south by Hamilton county. 
It extends to the Indiana line upon the west. | 
It is divided into two unequal divisions by the Great Miami River, 
the division lying west of the river being about twice as large as that 
on the eastern side. The river now pursues a general south-westerly 
direction through the county, but an earlier-formed channel diverges 
from the present valley opposite Hamilton and bears to the south-east. 
Within the limits of Hamilton county this older channel is known as 
Mill Creek valley, which divides at Cumminsville into two branches, 
one of which enters the Ohio on the western boundary of Cincinnati, 
and the other enters the little Miami valley at Red Bank station, on the 
- Little Miami Railroad. 
Part of another old channel is also found in the north-eastern corner 
of the county, adjacent to Middletown, which is connected with the 
Little Miami valley by way of Lebanon. Both of these ancient valleys 
have been turned t>» account within the last forty years for canal beds, 
the Miami Valley Canal from Cincinnati to Hamilton occupying the 
first named channel, the second furnishing the route for the unsuccessful 
branch from Lebanon to Middletown. Very little lockage was found 
necessary in either. 
The drainage of the eastern division of the county is mostly effected 
by streams of inconsiderable size. The tributaries of the Miami that 
enter upon the western side deliver the surface water of more than seven 
hundred square miles of territory. These streams have a remarkable 
agreement in direction, all of them flowing to the south-east. It is 
altogether probable that their channels owe much to glacial erosion, as 
