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I regard it my pleasant duty to express to these two gentlemen my sincere thanks for their unremitting zeal in topographical and other work, and for their ever cheerful endurance of hardships under the most trying circumstances.

I have the honor to submit with this a short preliminary report referring to those parts of my districts to which the work was mostly confined, referring particularly to the Hazel mine to prove that, besides the numerous outcrops, indications and prospects mentioned in former reports, actual mining is carried on in West Texas, not only in the more generally known Shafter mine in the Chinatti Mountains (Sierra Pitares), in Presidio county, but also in El Paso county, and thus to demonstrate repeatedly that Trans-Pecos Texas, far from being a valueless desert, deserves the fullest attention of the Legislature and of the administration of our State.

The mountains between the longitudes 105 degrees and 104 degrees 55 minutes west of Greenwich, lying between parallel 30:55 and the continuous high limestone cliffs about eight miles north of the Texas & Pacific Railroad, are generally called the Sierra Carrizo, and the mountain range extending north from the cliffs towards and partly alongside of the Salt Lake Valley and terminating at the Sierra Prieta are known as the Sierra Diabolo. This is here accepted as a correct definition of the two ranges.

The principal portion of the southern part of the Carrizo Mountains is built up of Crystalline Schists, such as talcose, micaceous, argillaceous and greenstone schists, with numerous quartz veins and occasional basaltic intrusions. These schists, which dip at angles varying from twenty-three to eighty-five degrees, are flanked on their eastern and southern slopes by limestones, which also appear, but less distinctly, in the west. These limestones are only slightly tilted, and rest not quite conformably, on a sparsely exposed, dark red or brownish gritty sandstone, in which no fossils have yet been found. Further east, toward Van Horn station, these grits extend in lower hills, denuded of the limestone. Some of these hills are considerably tilted, but evidently from having been underwashed and having slipped down.

The tilted condition of the schists is evidently due to the upheaval of granitic rock which in the passes between Allamore and Van Horn, and again on the western slope of this mountain group, eruptives appear in small patches below and between the schist rocks.

The limestones of the cliffs north of the Texas & Pacific Railroad rest in most places visibly but slightly unconformably, on red and brownish grits, alternating finer and coarser, and interstratified with layers of conglomerate cemented by a red gritty mass. The thickness