The Sulphur Bank Mine is located near Clearlake Oaks and Clear Lake in Lake County, California. The mine became one of the most noted mercury producers in the world.
During the 150 years since the Sulphur Bank was discovered, the area has drawn geologists, inspired unique scientific theories, established constitutional case law and now attracts environmental scientists who study the impact of mercury contamination within the Cache Creek watershed of northern California and the Sacramento River-Delta Region and San Francisco Bay.
History
Beginning in 1856, the mine was first worked for borax. Mining for sulfur began in 1865, and produced 2,000,000 pounds (909,090 kg) in four years. Mercury ore was mined intermittently by underground and open-pit methods from 1873 to 1957. Sulphur Bank Mine was credited with a total output of 92,400 flasks (7.02 million pounds) by 1918. The mine was an important producer during both world wars.
The mine closed in 1957 and is a California Historical Landmark (#428). Sulphur Bank Mine became an Environmental Protection Agency (EPA) superfund site in 1990.
California Borax Co.
Although the hot springs of the Sulphur Bank contained borax, the search led John Allen Veatch to nearby Borax Lake where the California Borax Company established the first commercial borax mining operation in the U.S. beginning in 1860 and ceasing in 1868. The company established land claims to Borax Lake, the Sulphur Bank and Sulphur Springs in Colusa County.
The officers of the California Borax Company included physicians Veatch, William Ayers and Robert Oxland; and lawyers Henry Halleck, Archibald Peachy, Frederick Billings and Solomon Heydenfeldt. The fascination with borax resulted from the fact that boric acid was critical as a flux in metal working. All borax at that time was imported, mostly from the Tuscan Lakes area of Italy. The California Borax Company did engage in sulfur mining at Sulphur Bank (extracting 2 million pounds in 4 years)<ref name="qscalif63"/> for a time before the company’s collapse in 1868 and the sulfur was discovered to be contaminated with cinnabar.
Discovery of cinnabar
Between the time of Veatch’s discovery and the working of sulfur, a minor mining excitement led to the discovery of cinnabar in the northern reaches of Napa County (of which Lake County was then a part). The Silverado rush in the winter of 1858–59 caused “every unemployed man from Soscol to Calistoga turned prospector. Blankets and bacon, beans and hard bread rose to a premium,” reported William T. Montgomery in a light-hearted sketch of the great silver rush that resulted in enormous finds of worthless iron pyrites. But the rush did result in the discovery of cinnabar in 1860. Montgomery, who became a stockholder in the X.L.C.R. (pronounced "excelsior") mine, is the only known source of the often-repeated tale of Seth Dunham and L.D. Jones discovering cinnabar in a road cut of the Barryessa–Lower Lake Road (now Morgan Valley Road) in what became known as the Knoxville mining district, about a dozen miles southeast of the Sulphur Bank in present-day Napa County. The X.L.C.R. became known as the Redington mine a decade later and was second only to the New Almaden mine in production.
Another account of the discovery of cinnabar in the same region is contained in the December 1861 edition of Scientific American magazine. “There has been recently opened an extensive cinnabar vein, in Napa County, which promises to be rich. This was discovered by John Newman, of Pope’s Valley. The cinnabar was discovered by means of the fires which are made to burn off the chaparral,” the magazine reported.
Newman became a stockholder of the Phoenix mine in that location. These early discoveries of mercury-bearing ores did not become viable mercury producers until 1872, when the price of mercury and improved smelting methods resulted in the establishment of many mines in Lake and Napa counties.
John and Tiburcio Parrott
In 1873, the defunct California Borax Company was acquired by Tiburcio and John Parrott, William F. Babcock and Darius Ogden Mills, for the purpose of quicksilver mining at Sulphur Bank. Until 1875, when the mine shipped 5,218 flasks of mercury, it operated under the name of the borax company but then changed the name to the Sulphur Bank Quicksilver Mining Company.
Tiburcio Parrott was controlling partner of the new company, and it was he who was later jailed when the company refused to abide by a state law excluding Chinese from employment.