The Arizona sentinel., 1901-01-23
CASTLE DOhIE DISTRICT.

The veins of the Castle Dome district may be said to have been rediscova1el 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 sorlc -lGccs for 50 to 1O0 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 C some rude smelling furnaces, indicate that the crcs were carried to the Gila probably on the backs Of Indians and that they were snclte& the-e. whether by the AZtecS or the early-arriving Spanish explorer is not known. Since 1863 these mines have hcnn worked almost continuously and are now yielding silver-lead ore of most excellent quai,ry which is shipped 10 San Francisco. 1Ee claims were worked by the prosPectorS without capital until October, 1870 Up to January l. 1892 there had not been cr investment of over $500 in building or per manent Improvements. Inc climate is such that men can work the year round without no mOIC r-3.ect!Ol than is afforded by brush, hutS Cc tens.
 The veins crop out on rolling plain or mesa at the base of tl:e Castle Dome range, a very rugged and pictlreS lue group of mountains trending northwest and southeast. rising, near the center to the remarkable dOme-Shaped sum init with precpitous sides. looking like a huge round castle or building with Q dome. It is noted landmark, being visible from a great dis tanco in oil directionN It was originally called Capitol Dome by the officers at Fort Yuma in 1853, from the fGncied resemblance to the dome of the capitol at Washington. This mountain range, being but spaTingly 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 Cila 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 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 ge-er,., northwest and southeast course and a-e nearly vertical. The outcrops are in dica:ad by outlying masses and weather worn crystals c. Goarsp2r. which is the chief vct-T.c2o. CGlci,c and -T n-,iln are also found
 
 stone of quartz dispersed iA sheets or combs" aIonC the walls or in distinct sheets in the center. Manganese spar and barite arc also as sociatod 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. h general the veins arc veil filled with ore. This ore occurs in sheets O. b-Aches 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 watec level, where the galenite has dao5nYoa2L both caroonate and sIlpAate Of Tad arc f912d associated with pale-green 1uoritc and an abundance Of cryStallizod yellow wuifenitc, another occurrence giving cyidenc" of the presence of molyblonU,n in galani.e.
 The rocks of the district are compact fine grained mica and clay slates ssalliay nearly OF edge and travo-sea 1y numerous dikeS CT intru- sive masses of a chocolate-colored porphyry.