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VALLEY OF THE MIMBRES RIVER—AGUA CALIENTE. 
VALLEY OF THE MIMBRES RIVER. 
The Mimbres river lies in a depression or fault in the strata, which have been upraised imme¬ 
diately east of the stream, and which forms the elevated, rolling plain lying between the river 
and the Pichaco de los Mimbres. "Where the trail crosses the river, on its left bank, are several 
low mounded hills with their bluffs to the west, and two rugged masses of porphyritic trachyte 
rock. Higher up the stream to the east these rugged hills with porphyry dykes are more 
abundant, and form, with the sedimentary rocks upheaved, the oak covered hills, in which the 
Mimbres has its rise. On the right bank of the river is spread out a great exposure of whitish 
and red sandstone, broken through by porphyritic amygdaloid, which latter is scattered over 
the surface. North of this, and separated by an interval of 20 miles of rising and rolling 
ground, lie the Copper Mine mountains. To the north and west is a wide and open plain, whose 
long axis is northwest and southeast, reaching to the Burro mountains, south of which lies the 
undulating, rough prairie, leading to Ojo de la Vacca and Ojo de Inez. This portion of the region 
is covered superficially by the white and red sandstone, already described, near Ojo de la 
Yacca.—(Plate XIII, fig. 3, illustrates the structure, and fig. 2 gives a section of the river bank.) 
Between these two points, the Mimbres and the Ojode la Yacca, and close to the trail leading 
from the former to the Copper Mines is that remarkable warm spring known as “ Agua Caliente;” 
it lies about five miles from the river, and its position is easily found from the fact of a single 
cotton-wood tree growing beside it; as there are no trees for some miles around, it is easily 
recognized. A few osiers are scattered around the margin of the springs, which lie in a narrow 
valley. Where the springs issue out is a mound or bank of tufaceous deposit, formed by the 
overflow of the waters of the spring at some former time, previous to the side channels being 
formed. This mound is 20 feet above the valley level, and 2^ feet above the level of the 
water in the spring, showing that the spring, by the deposit of carbonate of lime from its waters 
has formed a basin wall for itself, and allowed its level to be raised above the surrounding valley. 
This calcareous basin is 25 feet across, and does not show bottom, except round the edges, 
which are rocky ; a twelve foot pole thrust in toward the middle did not find bottom. The tem¬ 
perature of the spring was 130° Fall, at the surface, and was very painful to the fingers when 
immersed more than a minute or two. Loosely attached to the sides and floating in the water 
were thick, fleshy confervas, green above and red on the under surface. From one point below, 
bubbles of gas rose in great abundance ; some of these collected in a tin vessel were without sul¬ 
phurous odor ; the gas extinguished a taper and did not inflame, and was therefore carbonic acid. 
Since this basin was formed, four small channels have been bored through the tufa wall, and 
open out a few yards down on each side of the main spring. Through these rolls out the 
water some paces down into little reservoirs, resembling artificial baths ; to the inaccurate 
observer these might appear to be distinct springs, but close observation will show they are 
derived from the central spring. In these little channels the water does not attain the same, 
height of temperature. They read 108°, 110°, 115°, and 120°, respectively, in proportion as 
their channels of communication through the tufaceous deposit is more or less long. A large 
body of water flows off from this spring, and were it situated within the limits of civilization, 
it might be made available for medical or economic uses. 
The water is agreeable to the taste.* 
* It is to be regretted that a bottle of this water, filled on the spot, was broken, after having been carried several weeks, so 
that its exact constitution cannot be determined. However, at the close of six weeks, this water had preserved its transparency, 
