Page 44 - The Geology and Ore Deposits of Sierra County, New Mexico - Bulletin 10

GENERAL FEATURES 43
copper, lead and zinc, and many of the old camps of the county again became active. During the present century a small annual production of metals has been maintained, which has varied con- siderably from year to year, following the trend of prices. In 1903 gold was discovered in the Pittsburg (Shandon placers) district near the Rio Grande, and from time to time discoveries of small but high-grade lode deposits were made, which spurred prospectors to renew activity for short periods. Mining in the county was not stimulated by the World War but revived mod- erately during the period of 1920 to 1923.
During the summer of 1931 a discovery of placer gold was made on the east slope of the Sierra Caballos, near Apache Gulch. By early fall, the Lookout mine in the Tierra Blanca district, owned by W. D. Slease of Hillsboro, and the Bonanza mine near Hillsboro had resumed operations, producing Alver-telluride- gold and gold-copper ores respectively. In 1932 and 1933 placer ground near Hillsboro was worked experimentally on a large scale, and the Shandon placers were sampled and equipment in- stalled. During this same period the El Oro mine in the northern end of the Hillsboro district was unwatered and a modern new shaft, power house and 300-ton capacity mill were installed and equipped.
During the winter of 1931-1932, owing to the financial de- pression and consequent lack of employment, many miners returned to the hills to prospect and lease on a small scale, and in 1933 Sierra County presented a picture of mining activity such as had not been seen since the period immediately following the World War.
The extremely interesting details of the history of this region and of the mining development within it may be gleaned from the following references, from which much of the material here appearing has been taken :
Bolton, H. E., Spanish Exploration in the Southwest, 1542-1706, 1930. Bancroft, H. H., Arizona and New Mexico, History of Pacific States of North America, vol. 12, 1888.
Prince, L. B., Historical Sketches of New Mexico from the Earliest Records to the American Occupation, New York, 1883.
Jones, F. A., New Mexico Mines and Minerals, Santa Fe, N. Mex., 1904. Lindgren, Waldemar, Graton L. C. and Gordon, C. H., The Ore Deposits of New Mexico, U. S. Geological Survey Professional Paper 68, 1910.
PRODUCTION
In the late seventies and early eighties, immediately following the discovery of ore in Sierra County, the annual production from this area probably exceeded that of any other county in the State. From 1884 until 1888 the production was in close competition with that of Grant County, and the lead appears to have alternated between these two counties. After 1888 and until 1893 the production of Sierra County remained at a fairly con- stant level, while that of Grant and Socorro counties steadily