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Ohio Biological Survey 
(Quercus macrocarpa), and white ash (Fraxiniis americana) occur with 
beech. 
In the upper Mill creek valley area, low hills are built up above the 
general level; in the Norwood trough, valleys are cut beneath it. The 
soil of these hills—a compact but gravelly till without a covering of 
loess—is more porous than the Illinoian till and the loess of the Norwood 
trough. These two factors—relatively small area of hill top, and porous 
soil—tend to make the water table lower than in areas of equal or even 
greater relief in the Norwood trough, and therefore, the forests less 
mesophytic. 
Many of the streams in this area wander among the hills, finding 
rather than making their valleys. The larger streams which cross the 
area have, however, cut fairly deep valleys in the till. These valley slopes, 
though gentle (6-10 degrees) are not clothed with beech forest, as was 
the case on ravine slopes in the Norwood trough. In fact, beech is 
always entirely absent, for the porous soil of this gravelly till drains 
readily. The forest here is composed of oaks (Quercus Muhlenhergii, 
Q. velutina, Q. texana, and Q. alba), sugar maple, walnut, and white ash. 
A short distance back from the edge of the ravine slopes, beech is again 
dominant. 
3. The Miami-Whitewater valley 
Much of that part of the Miami-Whitewater valley covered with till 
of Wisconsin age, is flat. In places there is a poorly-developed sag and 
swell topography. The valley filling is partly water-laid; gravel is an 
important component in much of the area. 
Streams start in indefinable depressions much as do those of the flat 
uplands. Their margins are swampy and they are bordered by willows 
(Salix nigra and N. longifolia), cat-tail (Typha latifolia), ditch stonecrop 
(Penthorum sedoides), swamp milkweed (Asclepias incarnata), monkey 
flower (Mimuhis ringens), and boneset (Eupatorium perfoliatum). 
The area is little dissected, except near the margins adjacent to the 
low-lying flood plains. These slopes are terrace edges, and as the till 
contains a relatively high percentage of gravel, the vegetation is that of 
gravel slopes. 
The forests of the Miami-Whitewater pre-glacial valley are essentially 
like the mixed forests of undrained uplands. Here, as on the uplands, 
is a pre-erosion forest type. Groups of red maples (Acer rubrum) occur 
in a mixed forest of oaks (Quercus alba, Q. velutina), sugar maple (Acer 
