A “Great Drought” from 1862-65 destroyed the cattle-based economy of our region. Then it received a boost from a “quicksilver rush.”
That “boom” attracted the interest of George Hearst and the enduring interests of the Hearst family in San Luis Obispo County.
Mercury ore is called cinnabar. The Salinan Native Americans used the ore to produce an orange and red-hued powder for painting rocks and portions of their bodies. Cinnabar was readily found in the Franciscan layer of sandstone, a brownish stone that was known to be the matrix for cinnabar ore. The layer runs the length of the Santa Lucia Range.
Franciscan padres Luis Antonio Martinez at Mission San Luis Obispo and Juan Cabot at Mission San Miguel were said to have had flasks of quicksilver, possibly for medicinal purposes common in the early 19th century. The presence of the silver colored liquid may be one of the sources for stories concerning “Franciscan silver mines” that I wrote about in last week’s column.
Until the discovery of gold in the Mother Lode, mercury had relatively few uses in California.
Mercury-coated copper plates were the principal method used to amalgamate and thereby extract gold and silver from crushed ore, creating a heavy demand for quicksilver to meet the needs of the gold mines in California’s Mother Lode and the silver mines in Nevada’s Comstock Lode.
During the Civil War, 1861-65, the price of mercury soared. It was needed to process the Nevada silver, which helped pay the costs of the Union forces. Mercury was also used in the manufacture of detonating devices, most especially for the percussion caps, which were being used by the millions on the rifles of both the Union and the Confederate armies. The principal source of cinnabar was the New Almaden Mine on the southwestern side of the Santa Clara Valley. The New Almaden’s supply couldn’t begin to meet the demand for the slippery metal.
Even the opening of the New Mercury Mine in the Mt. Diablo Range south of San Juan Bautista in 1854 couldn’t meet the needs of the gold and silver mining operations. The start of the Civil War in 1861 caused the price of mercury to soar.
In 1862, a party of Mexicans discovered an outcropping of cinnabar near the headwaters of Cambria’s Santa Rosa Creek in the Santa Lucia mountain range. This was the beginning of the Josephine Mine, the first important mining operation along the Central Coast.
Hundreds of miners arrived from other parts of the West. They staked out claims in adjoining locations. Barron & Co. of San Francisco, former part owners of the New Almaden near San Jose, purchased the Josephine.
George Hearst, whose fabulously successful Ophir Mine at Virginia City had “made” the Comstock Lode, didn’t want the cinnabar magnates like Barron & Co. to monopolize the market. He purchased the Piedra Blanca Rancho nearby the Josephine Mine. The rancho had been destroyed by the Great Drought and Hearst was able to buy it for less than a dollar an acre.
Like most California landholders who made money on their land, Hearst was prepared to hold on to what he bought. Following Lee’s surrender at Appomattox, the price of mercury dropped by 200 percent. Barron & Co. suspended operations.
Hearst knew that his lands held vast reserves of cinnabar for when he needed it. When the world price of mercury went up after the Franco-Prussian War, he was pleased by the discovery of the Oceanic Mine, a source of far richer cinnabar ore than the Josephine. It was also more accessible to ocean transport as its maritime name suggests.
And except for the small portion granted to the state of California to form Hearst San Simeon State Historical Monument in 1957, the Hearst Corporation still owns the land acquired in 1865.