Holly Ash Mine / Calsilco Mine

During the late 1800s and early 1900s, miners discovered the pumice which was used in household cleaners like Holly Cleanser. The pumice was pulverized into an ash, and the mine draws its first name from the process. It’s other name comes from the Calsilco Corporation who operated the mine in the first half of the twentieth century. Today, you can still see the striking, cave-like holes in the mountain face where minerals were removed by miners. The Calsilco pumice deposit is a layer of sedimentary pumice lapilli tuff which lies below red andesite agglomerate.

“The Calsilco deposit was first worked by an unidentified concern from 1919 to 1945, then briefly by the Insulpum Corporation, and since 1946 by the Calsilco Corporation. Total production is greater than 25,000 tons of raw material. The raw material was being mined intermittently in 1958, milled and bagged on the property, and hauled by truck to Los Angeles or rail siding… The finished products have been used in insulating and acoustical plaster, cleaning compounds, wood and paint fillers, toothpaste and powders, soil conditioners, and oil-absorbing compounds. In 1958, most of the finished material was sold for use as paint filler and oil-absorbing compounds…”

-Excerpt from Mines & Mineral Resources of Kern County.

You can find this Discovery Point via GPS at N35.4483, W117.8980, or in section H-9 with the Jawbone Canyon OHV Map.

Dedicated to Ed Waldheim

Founder of the Friends of Jawbone (FOJ)

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