60 GEOLOGICAL RECONNOISSANCE 
The ridges, 150 to 160 feet above the white sandstone, which crops out 
near Sander’s store, and elsewhere in the Barrens, are mostly strewed with 
agatized and chalcedonized chert. These are either destitute of timber 
or overgrown with thickets of low scrubby timber, while the narrow, tor- 
tuous vallies or “coves,” enclosed between the ridges, are, for the most 
part, meadow prairie. 
Though rocky and rather forbidding, at first view, the land produces 
well; particularly oats, wheat, wool, and honey. The crops of maize may 
be considered average. The country is well watered, and possesses many 
fine water-powers, even at the very fountain head of some of its numerous 
limpid calcareous streams, which frequently burst forth from amongst the 
ledges of rock. 
One of the most remarkable of these, forms the fountain-head of the 
main fork of Spring river, known as the “Mammoth Spring,” welling up 
on the south side of a low rocky ridge, from a submerged abyss beneath 
of sixty-four feet, and constituting, at its very source, a respectable lake 
of about one-sixteenth of a mile from north to south, and one-fifth to one- 
sixth of that distance from east to west. 
It is said, by those that have sounded the bottom, that there are large 
cavities and crevices in the rock, and that the main body of the water 
issues from a large cavernous opening of some forty yards in circumfer- 
ence. It has been estimated that it boils up at the rate of about eight 
thousand barrels per minute; the correctness of this estimate, we had no 
means of verifying; but it may be safely estimated, that the average 
constant flow would be at least sufficient to propel from 12 to 15 run of 
stones. 
The uniform temperature and composition of the water, is peculiarly 
congenial to the growth of a variety of cryptogamic, aquatic plants, pos- 
sessing highly nutritive qualities, both for herbiverous animals and birds. 
In the early settlement of the country, herds of herbiverous wild 
animals traveled from great distances to this fountain, of both food and 
water, as well as flocks of wild fowl. Now, the cattle of the neighboring 
farms may be seen wading in its waters, up to their middle, and browsing 
on the herbage, which appears peculiarly congenial to their tastes; it is, 
also, a general resort of ducks, geese, and other aquatic birds. 
This mammoth spring is located just south of the east and west line 
between Missouri and Arkansas, on section 5, township 21 north, range 7 
west of the 5th principal meridian, and forms the most interesting feature 
of this section of country, since it affords a water-power, which, if properly 
improved, might supply valuable mill-sites, and water-privileges, for 
manufacturing purposes in general. Small and rude as the-present grist- 
