From "Mines and Prospects of the Andrews Mountain, Mazourka, and Paiute Roadless Areas, Inyo County, California," U.S. Geological Survey, 1987, by Steven W. Schmauch:
Summary: Fractures filled with quartz from irregular, discontinuous veins and pods in a 160- by 340-foot area of thinly bedded slate. Massive and cubic galena with minor amounts of sphalerite and pyrite are unevenly distributed in the quartz.
Workings: Eleven pits, three adits totalling 220 feet of underground workings and three shafts 14, 28, and 43 feet deep.