The Arizona sentinel., 1900-09-26
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 probaaly 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 i 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 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-Snaped 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 sparngly 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 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 general northwest and southeast course and are nearly vertical. The outcrops are in- dicated by outlying masses and weather worn crystals of fourspar, which is the chief veinstone. Calcite and gypsum are also found, and in some of the veins there is vein- oSOhO Oi qudi II uISpOASOO III SuCCIo UT JULIUS
 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- 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 palegreen f1uorite 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 dilzes or intru- Sive masses of a chocolate-colored porphyry.