The Arizona sentinel., 1900-11-07
CASTLE DOME DISTRICT.

The veins of the Castle Dome district may be said to have been rediscovered in 1863 for it was evident that they had been anciently worked. as already stated in the historical introduction. The metal had been taken out from many of the veins by the ancient miners down to a depth of from to 15 feet and in continuous lines of trenches, in some places for 50 to 100 feet or more. These old workings were found to be safe guides to good metal bearing ground a short distance deeper. Well worn trails leading of from these pits to the banks of the Gila river, some IS miles distant, and the ruins there of some rude smelling furnaces, indicate that the ores were carried to the Gila, probably on the backs of Indians, and that they were smelted there, whether by the Aztecs or the early-arriving Spanish explorer is not known. Since 1863 these mines have been worked almost continuously, and are now yielding Silverlead ore of most excellent quality, which is shipped to San Francisco. The claims were worked by the prospectOrs without capital until October, 1870. Up to January I, 1899, there had not been an investment of over $500 in building or per manent improvements. The climate is such that men can work the year round without no more protection than is afforded by brush, huts or tents
 The veins crop out on a rolling plain or mesa at the base of the Castle Dome range, a very rugged and picturesque group of mountains trending northwest and southeast, rising near the center to the remarkable dome-shaped sum- init with precipitouS sides, looking like a huge round castle or building with a dome. It is a noted landmark, being visible from a great dis tance in all directions It was originally called Capitol Dome' by the officers at Fort Yuma in 1853, from the fancied resemblance to the dome of the capitol at Washington. This mountain range, being but sparingly watered, has never been convenient to prospect and very little is yet known of its structure or mineral value. The mines are usually reached from Yuma by driving to Gila City and thence to the mine, from 16 to IS miles east and inland from the river. The claims are numerous. Some have been patented and worked to a depth of 300 feet or more. The veins are re- markedly regular and well formed. The ore is galena, carrying about 30 ounces of silver to each ton. The veins trend in a general northwest and southeast course and are nearly vertical. The outcrops are in- 5icated by outlying masses and weather worn crystals of fiourspar, which is the chief veinstone Calcite and gypsum are also found,
  stone of quartz dispersed in sheets or combs along the walls or in distinct sheets in the center. Manganese spar and barite are also as sociated in layers. The thickness or power of these veins is usually from to feet, sometimes from to 12 feet, wide. There are veins also only few inches in width. In general the veins are well filled with ore. This ore occurs in sheets or punches scattered through the vein &1,o, as ball metal. In one mine in the district mass of nearly solid ore feet thick was found.
 At or near the water level, where the galenite has decomposed, both carbonate and sulphate of lead are found associated with a pale-green fluorite and an abundance of crystallized yellow wulfenite, another occurrence giving evidence of the presence of mOlybdenum in galenite.
 The rocks of the district are compact fine grained mica and clay slates standing nearly on edge and traversed by numerous dil1es or intru- sive masses of chocolate-colored porphyry.
 THE CHA VALLEY.
 The Gila valley extends from the Gila canyon near the junction of the San Pedro river, west erly to the east bank Of the Colorado, distance of slightly exceeding 25O miles. That portion of it situated in the county of Yuma, known as the | from to 10 miles wide, all of which is suscept ible of profitable cultivation. The river | from which it takes its name cuts the valley in two It's watershed extends some 3C miles north and upward of 50 miles south of its channel, the land from either extreme inclining more or less rapidly toward the stream. The | Gila traverSes a marvelously fertile country very great ill extent, and splendidly adapted tC the cultivation of nearly all the products of the temperate and semi-tropic zones, besides many of the fruits common in the tropics. Nor is this longer a matter of idle speculation, fol fourishing ranches in various portions of tho valley drawing water from several important canals, amply demonstrate the magnificent results that will enSue should the water supply be rendered permanent equable and adequate through appropriate storage systems.
 This consists of broad expanse of tillablt valley land, sometimes overf1owed by the river which is at times mighty uncertain, and a steer range of volcanic hills coming close to the high ways, for a dozen miles CT SC, hot. heavy, sandy It is hardly fair to say sandy as it is really friable alluvial soil of grayish hue and loos, texture. Several ranches are passed, showing
 that the Gila bottom is cultivated. With irri gation every square mile of the Gila valley i
 capable of producing prolific crops of grain anC semi-tropical fruits, as well as cotton and suga
 in great abundance. The river is able to fur nish all the water needed and good deal more It would take no great skill in engineering ant