The Arizona sentinel., 1900-10-10
CASTLE DOME DISTRICT.

| mica SlaCeS Serl6S r0lerreQ 70 IS the durOnlan or Archaan.
 l CASTLE DOME DISTRICT.
 The veins of the Castle Dome district may be said to have been rediscovered in ls6S 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 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 y-arriving Spanish explorer is not known. Since 1863 these mines have been worked almost continuously, and are now yielding silver-lead 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 l, 1892, 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 huge round castle or building with dome. It is a noted landmark, being visible from 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- markably 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 dicated by outlying masses and weather worn crystals of hourSpar which is the chief veinstone. Calcite and gypsum are also found and in some of the veins there is vein 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 l2 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- stone and commonly known among the miners 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 pale-green f1uorte 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 dikeS 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, a distance
 
 it situated in the county of Yuma, known as the Lower Gila valley, is about 100 miles long and from to 10 miles wide. all of which is suscept- ible of profitable cultivation. The river from which it takes it's name cuts the valley in two. Its watershed extends some 30 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 ~; very great in extent, and splendidly adapted to 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, for f1ourishing ranches in various portions of the 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 tillable valley land, sometimes overfiOwed by the river, which is at times mighty uncertain, and steep range of volcanic hills coming close to the high ways, for dozen miles or so, hot heavy, sandy. It is hardly fair to say sandy as it is really friable alluvial soil of grayiSh hue and loose texture. Several ranches are passed showing that the Glla bottom Is cultivated. With lrrl- gation every square mile of the Gila valley is capable of producing prolific crops of grain and semi-tropical fruits, as well as cotton and sugar 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 and not very large sum of money either to con- Struct reservoirs or lakes in which to receive and store the overflow. There are natural basins or dry lakes into which by simple means the water could be conveyed
 The lands situated in and about the Gils val ley may conveniently be classified as follows: First, the bottom or overflow lands; ?, slightly higher valleys lands ubjsct U 10 overflow; 3, mesas or sloping uplands; 1, high but cOmpar- atively level plains; 5, mountains.
 The bottom lands, as well as those slightly higher, stretch along either side of the Gila and Colorado rivers for varying distances north and south, until they meet the more elevated meSas which rise from the valley. The bottoms lie directly along the river and are subject to inun- datiOn annually. Immediately following the | subsistence Of the waters the local Indians were in former times accumtomed to plant corn, pun pl,ins. lIrUus aIsd other vegetables. These