In the Chorolque district is said to be the highest mine in the world, 18,696 feet above sea-level. The altitude of the colossal conical peak is 21,156 feet. In this mountain and its environment are veins of silver, tin, bismuth, lead, copper, bronze, kaolin, and wolfram. It is in the region of eternal snows, of never-ending winds, of intense cold, and of rarefied atmosphere. It is operated through a tunnel known as the San Bartholomew and an aerial railway, half a mile long, by means of which the workingmen descend and return to outer earth. A drawback to the exploitation of this region is the lack of transportation facilities, the nearest railroad junction, at Uyuni, being 95 miles. This difficulty will be overcome when the railway is built from Uyuni to Tupiza, as a short spur will enable connection to be made with Chorolque.
The mines in the neighborhood of Oruro were discovered in 1575. In the beginning of the eighteenth century, just before the War of Independence, in three years they paid to the Spanish Crown as the tax of one-fifth, $40,000,000, which would mean an admitted production of $200,000,000. In the district of Oruro are said to be nearly 5,000 abandoned silver mines. In the immediate vicinity of the city a score of silver and tin mines are in operation. The most important of these is the Socavon of the Virgin. This is owned by a Chilean company. The smelting, or amalgamation, works are located at Machacamarca. Since 1898 the process employed has been the use of hyposulphide lixiviation. The San José mine is located in a basin two miles from Oruro. It is controlled by a Bolivian company, is electrically lighted, and has a smelting establishment employing the Wetherill system by means of electro-magnetism. During several years the value of its annual output amounted to $1,000,000.
Under the law the mines are obliged to deliver in silver bullion the fifth part of the exploitation to the national mint for coinage, and the price is fixed monthly by the Secretary of the Treasury. When the drop in silver continued, Bolivia lowered its export duty, and finally, in December, 1902, silver bullion and minerals were freed from export payment. The present Bolivian silver production, which is 8,000,000 to 9,000,000 ounces annually, forms a very small proportion of the world’s total output. But with the building of railroads and the assured decrease of transportation charges, it is a safe prophecy that within a few years the output will be doubled, if not quadrupled. Here Mexico again furnishes the illustration. In 1877 Mexico’s total silver production was $25,000,000, while in 1902, or a quarter of a century later, it had risen to $73,000,000, and this increase had been brought about very largely through the facilities afforded by the railroads, causing many old mines to be worked profitably and new ones to be discovered.
The copper deposits follow principally the course of the Andes from the Atacama desert through Lipez, Porco, Chayanta, and Calchas, northeast to Corocoro. The most important field is that of Corocoro in the Department of La Paz, 13,000 to 13,200 feet above sea-level. It is the Lake Superior region of Bolivia. The form in which the copper is most commonly met with is in small, irregular, spongy grains which are called barilla, and which are from 70 to 80 per cent pure. The native metal varies from the microscopic grains, or barilla, to great masses of almost pure copper which the miners call charqui. Other metals are found in combination. An analysis made in Hamburg gave the following results:
| Copper | 329 |
| Nickel | 175 |
| Silver | 9 |
| Zinc | 117 |
| Other substances | 370 |
| 1000 |
At times the mines of Corocoro have been exploited chiefly for the silver deposits, and their auriferous character also has been an element in their value. The claim is made that enough gold exists in the copper ore to pay the freight charges to Europe. The town has 15,000 inhabitants, and is the capital of the Province of Pacajes. The copper layers of this region are known in an extension of 35 miles. The mines are owned by Chilean, French, English, German, and Bolivian capitalists, to whom American syndicates make regular offers.
The production of the Corocoro district, in spite of discouraging markets, has mounted steadily. In 1879 it was 20,240 metric quintals, but in 1886 it had dropped to 10,000. In 1900 it was 25,636, and in 1902, 42,014 quintals, or nearly 1,000,000 pounds. The freight charges have been a heavy drawback to the industry. The two outlets from Corocoro are through Desaguadero River to Nazacara on Lake Titicaca, across the lake to Puno, and thence by the railroad to Mollendo and by ship to Europe; by pack animals to Tacna, and thence by rail to Arica and by ship to Europe. To Mollendo the cost of freight and insurance was 1.87 bolivianos (78 cents), while to Arica it was 2.24 bolivianos (96 cents) per quintal. The ocean freight to Europe from either point was about 2.78 bolivianos ($1.17). The building of the railroad from Corocoro to Tacna will afford the copper mines cheaper freights.
The government exacts a small export duty on the copper ore. The industry has promising possibilities in other regions, in addition to the increased development that may be looked for in the Corocoro district. The best paying of these is in Lipez, where the white native copper is produced and the ore treated simply by concentration.
There are three gold regions. The first extends from the western borders of the Republic, beginning in the basin of the Inambari River, to the upper Paraguay. It includes the mountain zone of Caupolican, Munecas, Larecaja, Cercado, Yungas, Inquisivi in the Department of La Paz, continues through the Department of Cochabamba, and is prolonged through Santa Cruz. There are some famed placer washings in this district, including the Suches and the Tipuani. The Suches is promising both for quartz and for placers. American gold-miners undertook to dive for the gold washings in the Tipuani, and they are said to have had a fair degree of success.
The Larecaja placers of Tipuani are historic. They have been worked since the time of the Incas. The Portuguese began to test them in the middle of the sixteenth century, and introduced negro laborers from Brazil. The Villamil family from 1818 to 1867 obtained 151,000 ounces of gold from the Larecaja properties controlled by them. The placers of the Yani River are also given considerable importance. The best-known mine in this section is the Elsa. The German mining engineer, Stumpff, estimated the quartz here at 61,000,000 tons, giving 36 cents of gold for each ton.