Bandarita Mine, California

The Bandarita Mine is a historical gold mine in the Mother Lode region of California. The property consists of seven unpatented lode claims and one mill site claim. The Bandarita Mine was discovered in 1856 and produced intermittently until 1943. It is credited with approximately 75,000 ounces of gold production. The main adit is accessible and the underground workings are extensive. Exploration potential includes 275,000 tons of broken ore in the old stopes and unmined and undiscovered portions of the Goodwin shoot which reputedly averaged 0.57 oz/ton gold.

From the California Journal of Mines and Geology, Volume 53, Numbers 1 and 2, January-April 1957:

"The Bandarita mine was discovered in 1856 (Browne, 68, p. 33) by Thomas E. Palmer and profitably worked almost continuously for more than 30 years. During the first 20 years the Goodwin Brothers and Peter Wynant were the principal operators. In 1873 operation of the mine was taken over from the Goodwins and Wynant by a San Francisco company under management of a man named Hanagan (Eng. and Min. Jour., 1873, vol. 16, no. 26, p. 412). By 1874 management had reverted to the Goodwin Brothers (Min. Sci. Press, 1874, vol. 29, no. 9, p. 133) who in a single mill cleanup took 25 pounds of gold from 100 tons of ore! By August 1876 management of the mine had passed to Levi Keyes, presumably still under ownership of the Goodwin Brothers (Min. Sci. Press, 1876 vol. 33, no. 10, p. 157). More than $160,000 was spent for mine machinery between 1872 and 1876 entirely from proceeds of the mining operations. About Jan. 17, 1880 a new 10-stamp mill run by water power was put into operation (Min. Sci. Press, 1880, vol. 40, no. 3, p. 37). Ownership passed to P.P. Mast of Coulterville about this time and C.L. Mast took over as superintendent. The Masts began to drive a tunnel from the level of the mill to crosscut the main vein 1200 feet from the surface outcrop (as measured along the vein). This ultimately reached a length of 1364 feet and encountered ore averaging $25.00 per ton. According to Julihn and Horton (1940, p. 141), the period 1881 to 1887 was the most productive in the mine's history. By 1889 most of the ore above the lowest tunnel level had been stoped out and the mine became idle (Eng. and Min. Jour., vol. 42, no. 22, p. 407). Intermittent work was done from 1890 to 1898. Early in 1898 Lafayette Gold Mining Company of San Francisco leased the mine with the idea of cleaning out the lowest tunnel and sinking lower from the tunnel level (Eng. and Min. Jour., vol. 65, no. 8, p. 229). Little is known of the results of this operation, but by 1904 ownership had passed to Rodgers and Loomis of Springfield, Ohio. There is no record of work of any extent on the mine from 1904 to 1928 when ownership passed into the hands of Gentry Gulch Consolidated Mines Company of San Francisco (Laizure, 1928, p. 89). This operation was apparently short-lived and there is no known record of production from the Bandarita mine at that time. About 1937 the mine was leased from the owners, Nelson M. Leoni and J.E. Brown, by four partners, William Beatty, W.M. Boyer, Carl Crouse, and G.A. Ogden (Julihn and Horton, 1940, p. 141) who operated the mine until 1943. Since 1943 the mine has been idle.

The Bandarita mine is credited with a total production of $1,520,000 much of which was mined between 1881 and 1887, according to Julihn and Horton. During the last period of activity, from 1937 to 1943, approximately $40,000 in gold and silver was obtained from 7362 tons of ore (U.S. Bur. of Mines records), the tenor of the ore being $5.42 per ton or considerably lower than ore milled in the 1880's.

The principal vein at the Bandarita mine strikes N. 84 degrees W. and dips about 47 degrees S. Its width varies from 2 to 10 feet. Wall rocks are slate, quartz-biotite, hornfels and granitic dike rocks. The metasedimentary series has been assigned to the Paleozoic Calaveras formation (group) by Turner and Ransome (1897).

In addition to native gold the ore contains pyrite, galena, sphalerite, and tetrahedrite, the best ore containing considerable tetrahedrite. Presence of tellurides, mentioned by S. Rudolph (Min. and Sci. Press, 1880, vol. 40, no. 11, p. 162) has not been confirmed by later writers. Julihn and Horton (1940, p. 141) visited the property in 1938 and the following data is drawn largely from their report. There are four granodiorite dikes which strike roughly north and intersect the vein approximately at right angles to it. The vein has been faulted at these intersections with throws of 1 foot to 42 feet.

The mine is developed by a 1364-foot crosscut adit, the portal of which is 50 feet above the river level, and by six adits driven along the strike of the vein, two on the east side of the hill and four on the west slope of the hill. The longest of these adits, 800 feet in length, is driven into the east slope and taps three ore shoots stoped from the surface to various depths between 75 and 650 feet. The crosscut adit taps the vein about 850 feet vertically from the surface or 1200 feet as measured along the vein.

In 1938, lessees stated that there was 275,000 tons of gob (broken ore) in the old stopes of the mine that would pay to mill at costs prevailing at the time and at the prevailing price of gold. The lessees were, however, mining unbroken ore from the Goodwin shoot which was reputed to average 0.57 oz. of gold per ton."