26 ON THE TIMBER LANDS TRAVERSED BY A 
beam (true iron-wood) abound. On the long, high level 
above the cave the principal timbers are red, black, and 
Spanish oak. They are worthless except for fire-wood. 
In the immediate vicinity of Mammoth Cave, and crowning 
the hill-side facing Green river, above and below it, the tim- 
bers are red oak, liriodendron, chestnut (on sandstone or its. 
detritus), white hickory, white oak, black walnut, blue ash, 
an occasional sugar and rock maple, winged elm, &c. At the 
base of the hill, on Green river, are beeches, sycamores, spice- 
wood (the first met with), white hickory, liriodendron, and 
white oak. Black sumach, woodland huckleberry, buckeye, 
dogwood, &c., are among the small growths. 
About two miles from Mammoth Cave, toward Cave City, 
the hill-tops are poor, and are covered with Spanish oak, scar- 
let oak, black-jack, and an occasional mountain oak. In the 
sink-holes and on their steep sides grow splendid chestnut, 
pig and white hickory, liriodendron, some white oak, post oak, 
and black locust. The chestnut is found only on the sand- 
stone. These upland and lowland timbers alternate, without 
any changes worthy of note, except occasional swamp chest- 
nut oaks, Bartram oaks, laurel-oaks, and black hickory, until 
we begin to ‘pass into the present eastern barrens, about 
twelve miles from Cave City, and within about eighteen miles 
of Greensburg. White oak and chestnut cease to exist, except 
the former on streams, &c., and a repetition of the barren 
timbers of the Purchase occurs. There seems to e a neck 
of country about Mammoth Cave which has, for some reason, 
more or less escaped the ravages of fires. 
Nothing else of interest occurs until we begin to pass from 
the cavernous St. Louis limestone onto the Keokuk limestone, 
sixteen or eighteen miles from Cave City. The change of 
formation first attracts attention by the circular sinks begin- 
ning to fade away into valleys, and the steep cave-hills into 
the more gently-rolling ones, due to erosion. The normal hill 
and valley topography gradually succeeds again the wonderful 
cavernous district, of which Mammoth Cave is the most widely 
known, if not the most interesting and instructive part. 
196 
