Besides these dazzling* discoveries; the Mono Lake district, which is ] oca ted at. tha junction of Calaveras, Mariposa ,and Fresno counties, is known to be a prolific field for mining operations, both in silver and gold; while it has been demonstrated' that the vast mountains of quarts which comprise the greater portion of Mariposa .county, known for their prolific g-olcl yield; are even richer in silver. A rich vein of silver has been traced across the nnrth-; eastern section of Mariposa county, on | both sides of the mountain range, which | leads to the belief that it is the .initiative ! of a:vast bod of silver ore on the west j side of the Sierra. In.. Calaveras county ! numerous discoveries of extraordinary [.richness have been made, and it is further \ stated that discoveries have been made ! as far east as the • Mohave and coloradp | rivers, which promise to be of vast im-j portanee.