Location and History
The Calistoga silver-gold district is in northwestern Napa County. Nearly all of the production has been from the Palisade mine, three miles north of Calistoga, and the Silverado mine, three miles farther north on the east flank of Mt. St. Helena. The district also has been known as the Silverado district, from the story Silverado Squatters, by Robert Louis Stevenson, who, with his wife, spent the summer of 1880 in a cabin at the Silverado mine.
Geology and Ore Deposits
Much of the district is underlain by volcanic rocks of Tertiary age. In places sandstone and shale are present. The ore deposits at the Palisade mine are in andesite, while those at the Silverado are in silicified rhyolite.
The deposits are in veins that consist of quartz and chalcedony, which often are brecciated. Some of the vein material is porous, and comb structures often are common. The gold usually is associated with silver, copper, and lead sulfides. The veins are steeply dipping, as much as 15 feet thick, and have been developed to depths of as much as 600 feet. Several highgrade pockets have been encountered.
Bowen, O. E., 1951, Geologic guidebook to the San Francisco Bay counties, Palisade and Silverado mines: California Div. Mines Bull. 154, pp.361-363.
Bradley, W. W., 1916, Napa County, gold and silver: California Min. Bur. Rept. 14, pp. 269-271.
Davis, F. F., 1968, Napa County, Palisade mine: California Jour. Mines and Geology, Vol. 44, pp. 183-184.