The Arizona sentinel., 1901-05-01
TERRITORY OF ARIZONA,
 nnIrATnNN nE VIM 4
CASTLE DOME DISTRICT.

The veins of the Castle Dome district may be said to have been rediscovered in l863 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 depth of from to Is 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-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 1, 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, 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 a 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 faneied 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 | vet 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 l6 to IS miles east and inland from the river. The claims are numerous. Some have been patented and worked to depth of 300 feet or more. The veins are re markedly regular and we'll 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 f1ourspar. 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 soeiated in layers. The thickness or power of these veins is usually from to 5feet, sometimes 1 from to 12 feet, wide. There are veins alsC l only few inches in width. In general the vein; are well filled with ore. This orc occurs 1T sheets or punches scattered through the vein
 stone and commonly known among the miner: as ball metal. In one mine in the district mas: of nearly solid ore feet thick was found.
 At or near the water level, where the galenitC has decomposed, both carbonate and sulphatt
 of lead are found associated with a pale-greer
 fuorite and an abundance of crystallized yellow
 wulfenite another occurrence giving evidenc' of the presence of molybdenum in galenite.
 The rocks of the district are compact fine
 grained mica and clay slateS standing nearly ol
 edge and traversed by numerous dikes or intru
 sive masses of chocolate-colored porphyry.