In 1977, when the price of tungsten hit one of its highs, three of us formed US Western Mines to look for scheelite, the mineral ore of tungsten. Union Carbide Corporation was purchasing raw tungsten ore at its treatment plant north of Bishop, California. Our effort figured to be a quick-start underground operation, with very little investment.
The formula for making a profit in such a small mining venture is often slippery and can elude the pursuer’s grasp. Adequate quality and quantity of the resource are required. These factors include the concentration of values in each ton of ore and the number of tons in the deposit. The ore must be present at a site where mining is physically possible and legally permitted. This includes getting along with federal agency people to secure permits to mine on the public domain.
The door to a reliable market has to be open. A buyer who charges the seller excessive impurity penalties will cause hardship at the mine. Metal prices can change in the time between opening a mine and shipping products from it. Extraction equipment, from muck-sticks to air-operated slushers, must be efficient, paid-for, and cost-effective. The human effort required to put all these pieces together calls for a combination of hard work, good judgment, and mechanical ability. Of the many requirements contained in this formula, from resource quality to technical expertise, the absence of just one factor generally spells business failure.
Commodity prices are variable, letting the small miner jump in when metal markets offer attractive payment for delivered goods. For the past twenty years, this has been best illustrated in the small gold placer mine business. Tungsten mining, however, with its limited product markets, holds very little attraction for the small miner. Additional risks are realized when relying on continuous ore quality and quantity, particularly in the case of scheelite, the most common tungsten ore mineral. This material can be hard to distinguish in its host rock, making the grade of the ore difficult to measure visually during day-to-day mine operations.
As a first step, Western Mines made a literature search of the known tungsten sources in California. From this study, Kern County was chosen as the target area. The principal source of information was County Report 1, Mines and Mineral Resources of Kern County, California. This report, published in 1962 by the California Division of Mines and Geology, is comprehensive, accurate, and extremely informative. Not every state offers such an eyeful of its mineral resources.
Step number two for Western Mines was a visit to the old abandoned tungsten mines of Kern County, particularly around Lake Isabella. Scheelite glows bluish-white under ultraviolet light, so the team examined underground workings with a portable “black light.” Where workings were caved in, a tarp was placed over surface exposures and mined rock to permit use of the black light by the examiner under the tarp. Several choice areas were examined on the surface by black light at night to trace float, while carefully watching out for rattlers.
Two old underground workings, the Butte and the Pala Ranch, were staked. The Butte Mine had shipped over one thousand tons of ore in the mid-1950s. This claim was on Greenhorn Summit in Sequoia National Forest. The workings were cleaned out; track was laid; a company mine car and compressor brought in; powder and cap magazines blasted out and furnished with steel doors. New advances were made in the old heading at the rate of three feet per day in solid granite. Local labor from Wofford Heights was employed. Western Mines ran assays on mine samples back at the lab-office in Pasadena, California.
Within two weeks of opening the mine, twenty tons of ore were stockpiled and sampled for assay by Union Carbide. The ore contained a notable trace of green copper oxide on which Union Carbide had a limit. Another easily identifiable mineral was cinnamon garnet, which occurred in large, attractive crystals. The Butte Mine vein was 25-feet wide and carried, according to the Union Carbide assays, between 0.25 and 0.50 percent tungsten trioxide across the width. No payment was scheduled by Union Carbide for ore assaying below 0.5 percent, making ore shipment extremely risky. Because of the expense, upgrading the ore to several percent before shipping was not an option.
The Butte was shut down. The equipment was moved from the property to the Pala Ranch Mine, the second property staked by Western Mines. This property overlooks Lake Isabella. Some years before, the mine had been operated by Dr. Rene Engel, a registered geologist and retired professor of geochemistry from Cal Tech. Dr. Engel, who lived in nearby Wofford Heights, offered his considerable expertise to Western Mines by indicating where the richest ore might be found.
The Pala Ranch Mine had a forty-ton ore bin on the property, and room enough to load a 25-ton truck and trailer. The road to the nearby highway was repaired by hand, the ore bin stabilized, and the adit portal opened for mine car passage. The adit contained very little good ore and was for haulage only.
A raise was quickly driven and timbered to intercept the ore shoot. During drilling the drill cuttings were examined in a gold pan beneath the black light. When appreciable scheelite first appeared in the concentrate, the drilling in that hole was stopped. Seven holes were drilled, then shot simultaneously to expose the ore body overhead.
When the powder fumes from this blast had cleared out, we went in to have a look. Scheelite is not something easily picked out in white light. It lacks distinguishing characteristics. So we looked at unimpressive, freshly blasted rock by the glow of our miner’s headlamps. When we put the ultraviolet light on the newly exposed vein it was a different story. The vein looked like a sky-full of brilliant stars. We were in pay ore.
Production with two men working underground began immediately at the rate of ten tons per day. Waste and ore were sometimes shot and mucked separately on the same day. Selective mining controlled the tonnage output. Had that not been the case, the output would have been limited by the antique mining equipment used. The portable air compressor was an old Chicago Pneumatic bought from the Harry Briggs estate in Panamint Valley for a few hundred dollars. Harry brought it with him in 1938 when he moved into the area of the recently-developed (Canyon Resources) open pit gold mine carrying his name. The compressor was about fifty years old by the time it was towed behind a CJ5 to the Pala Ranch tungsten mine. The air drill driven by the compressor was an ancient Ingersoll-Rand widow-maker mounted on a screw-jack post—no air-leg drill or stoper here. Looking back at the cost of mine equipment, the analytical balance in the assay office was worth more than all the machinery at the mine put together.
The first 100 tons of ore from the Pala ran just under 1.0 percent tungsten trioxide, worth $82.70 per ton. The largest single cost was trucking, at $16 per ton to Bishop. The operation continued as long as the ore assayed over 0.5 percent. As selective mining became more difficult, the ore grade continued to decline. The decision to quit was made despite the possibility that the next drill hole blast could open bonanza ore. All risks were minimized. While closing the mine, a large quantity of low-grade marketable ore was left in place.
After three months of operation and no set-backs or major machinery purchases, the Pala mine was shut down. It had been a poor-boy operation from start to finish. For every dollar invested in the tungsten project a return of $3.00 was realized.
