Shortly after the Spanish American War, Col. John Jacob Astor, the American millionaire, became interested in the copper deposits of Pinar del Rio, which resulted in the establishment of several claims, none of which, however, were developed. Shortly after this a Mr. Argudin located claims known as Regelia and Jesus Sacramento, the former only two kilometers from that of the mine Matahambre. A small amount of preliminary work was done, but apparently proved unpromising. In 1912 Alfredo Porta, a well-known citizen and politician of Pinar del Rio, interested Mr. Luciano Diaz, a former Secretary of the Treasury and a man of some means, in a claim which he had denounced some eight kilometers back from La Esperanza, on the north coast of the province. Messrs. Porta and Diaz secured the services of an experienced mining engineer, Mr. Morse, who visited the district, made a careful survey of the claim, and informed the owners that in his estimate Matahambre was worthy of the investment of any amount of capital, since the grade of the ore, and the amount exposed through Mr. Morse’s preliminary work, was sufficient to place it in the list of paying mineral properties. Work began at Matahambre in the early part of 1913 under the technical direction of C. L. Constant, of New York. During the first year a number of galleries, only a little below the surface, were thrown out in different directions. Paying ore found in these galleries was very promising. The first two carloads of ore, shipped by rail from the City of Pinar del Rio to Havana, sold for a sufficient amount of money to pay for all of the preliminary work that had been done. In 1915, a shaft was sunk to a depth of 100 feet and afterwards carried down to the 400-foot level, where it about reached the level of the sea. Later this shaft was sent down 150 feet further. The ore taken out at the 400-foot level proved to be the highest grade of all found, although it is said that no ore was encountered at any depth that was not of sufficient value more than to pay for the cost of mining. In fact the percentage of gold and silver in many cases has paid for the expense of mining the copper. In 1918, six shafts, known as 5, 6, 7, 8, 9 and 10, were in operation, and all yielding excellent ore. There are some 15 different varieties of copper ore taken from Matahambre.