30 ON THE TIMBER LANDS TRAVERSED BY A 
At about two miles south of Hustonville the Cumberland 
sandstone dwindles away to a shaly bed about ten feet in 
thickness, overlaid by heavy deposits of Corniferous; and in 
starting through ‘Nigh Gap,” it’ gives out altogether, and 
the overlying Corniferous rests directly upon the underlying 
Cincinnati limestone. ‘Nigh Gap” is the passage-way over 
Muldraugh’'s Hill, starting from Rolling Fork. The base of 
the hill here is Devonian shale, which is succeeded by Keo- 
kuk limestone at a height of seventy-five barometric feet. 
The transition presents a marvelous change in the timbers, 
and brings into strong contrast the difference between these 
two geological formations, in their effects upon forest growths. 
On the shale the timbers are mountain chestnut oak, scrub 
white oak, sour-wood, red oak, a few beeches (right on the 
river), some rock maple, &c. On the Keokuk, immediately 
adjoining, and ona higher level, grow splendid forests of white 
oak, black hickory, chestnut, black locust, liriodendron, white 
and shag hickory, sugar maple, redbud, spicewood, mulberry, 
blue ash, black ash, black cherry, American linden or bass- 
wood (the first met with), black walnut, red haw, and the 
usual small growth. The exceeding variety and richness of 
these Keokuk timbers is worthy of note. As to the questions 
pertaining to distribution, as affected by height above drain- 
age, they become of the first importance from this point east- 
ward, and will be discussed and illustrated under a separate 
head further on in this report. 
After crossing Muldraugh’s Hill, we enter the counties 
(north part of Lincoln and Garrard) the forests of which have 
been almost completely cut away. There are only scattering 
patches of fenced-in groves, consisting mostly of black and 
blue ash, white oak, black walnut, pig and shag hickory, and 
hackberry, until Muldraugh’s Hill is reached again, near Big 
Hill, in the southern part of Madison county. The geologt- 
cal changes are numerous. Stanford rests on Cincinnati lime- 
stone, and this continues to be the formation in depressions 
for some distance. On the higher grounds Cincinnati (?) 
sandstone appears. 3etween Paint Lick and Irvine, and 
200 
