124 GEOLOGICAL RECONNOISSANCE 
hardly capable of grinding 30 to 40 bushels per day ; quite insufficient even 
for the accommodation of the immediate neighbors. The efficiency of 
this natural dam, running, as it does, from bank to bank, with just the 
proper inclination and a slightly diagonal direction, across the entire water- 
course ; the solidity of its natural masonry, destined to endure for ages; its 
situation in the midst of a valley, which though contracted in its dimensions 
by the mountain fastnesses that bound it on both sides, is, nevertheless fertile 
and capable of supporting a moderate population: all combine to make 
this natural mill-site an object of great interest, and its many advantages 
would justify the erection of a substantial building, fitted up with all the 
modern improvements in the machinery of a well-regulated business grist- 
mill; this would attract customers, not alone from the valleys of the differ- 
ent benschies of Lee’s creek, but also from the neighboring mountains, 
and more distant settlements, and contribute, perhaps, more than any im- 
provement that could be introduced into the country, to attract fresh popu- 
lation, and render the condition of its present inhabitants independent, 
comfortable, and agreeable. Notwithstanding the continual wear to which 
this member of the millstone grit series—more durable than its associate 
beds—is continually subject, not alone from the mechanical force exerted 
by the running waters of Lee’s creek, but from the almost irresistible 
power of expansion, caused by the alternate thawing and freezing of the 
water, continually permeating its mass; it stands yet, a monument of ages, 
bearing testimony to the strength and insolubility of the siliceous cement 
that binds the particles together, and the stability of the individual grains 
of which its substance is composed; and it affords, at the same time, a 
striking example how enduring architectural edifices may be made, if con- 
structed of such freestone, judiciously selected, well built, and strongly 
jointed with good mortar. 
The ridge, passed over about two miles from the Natural Dam, is about 
390 feet above Lee’s creek, and is composed, so far as can be seen, of sand- 
stones and shales of the age of the millstone grit; with, perhaps, a cap- 
ping of some of the lower members of the overlying coal measures. 
It is nearly of the same materials that compose the high range of hills 
above the town of Van Buren, which has a commanding view over the 
valley of the Arkansas. From these heights, in a clear day, Fort Smith 
can be seen, while the bluff opposite to it and the glistening water-line, 
marking the bend of the Arkansas river, where it emerges from Indian 
territory and sweeps past Fort Smith, can be distinctly seen at all times; 
also the distant range of hills, running from the Choctaw country towards 
Sebastian county, including the House and Sugar Loaf mountains; with 
the small prairie in the middle ground, which is said to be underlaid by 
