The Arizona sentinel., 1901-04-17
CASTLE DOME DISTRICT.

The veins of the Castle Dome district may be said to have been rediscovered in 1853, 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 l5 feet and in continuous lines of trenches, in some places for 30 to leo 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 probaaly on the backs of Indians and that they were smelted there, whether by the AZtccS 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 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 ct 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-shapcd sum- init with precipitouS sides. looking like q huge round castle or building with dome. It is a noted landmark, being visible from a great dis tance in all directions. IL was originally called at XuTna in 1853, from the fancied resemblance to the dome of the capitol at Washington. This mountain rarge, being but sparingly watered, has never been convenient to prospect and very little is yet known of it's 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 mile; east and inland from the river. The claims arc numerous. Some have been patented and worked to depth of 300 feet or more. The veins are re- marlIably 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 flouTspar. 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 i 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 ir sheetS ar lunches Scaf tered through the vein 1 stone and commonly known among the miners as ball metal. In one mine in the district mass ] of nearly solid ore 8 feet thick was found.
 At or near the water level where the galenite has decomposed. both carbonate and sulphatt | of lead are found associated with a paie-grccn fuoritc and an abundance of crystalli1ed yellow
 wuifenite, another occurrence giving evidence
 of tho presence of molybdenum in galenite.
 The rocks of the district are compact fine
 grained mica and clay slates standing nearly or
 edge and traverscd by numerous dikes or intru
 sive masses Of a choco!ate-colored porphyry