The El Alamo district has a long history of gold production. Claimed for Spain in 1535 by Cortez, Baja California was explored by the Jesuits, who built a series of missions the length of the penninsula, many of which were near mining sites worked by the Jesuit priests and the natives. The Jesuits seldom were required to answer to the Spanish crown authorities in Mexico City and did little to disclose their mining activities to the Spaniards or the amount of gold that they shipped to Rome.
In 1888 gold placers were discovered at, immediately north of El Alamo. El Alamo became the site of largest mining rush in Baja California history, making it at the time the largest town in Baja California. The town of Ensenada, the nearest port, was instantly revitalized by the rush, while the El Alamo-Santa Clara District became the leading gold producing region in the Baja. El Alamo had shops, a school, a newspaper and over a thousand residents. The following is from a newspaper article that appeared in the Lower Californian (Ensenada) on July 11, 1889:
HOW THE MINES WERE FOUND
"Last October Rafael Lopez went into the level plain known as Alamo Basin, which lies at the foot of Tomasa, Alamo, Rosario and Pinon mountains, and began to prospect for mines. Within a few weeks he had discovered the Ulises, Telemaco, Grandora, Princesa and Cocinero. He said nothing, but kept steadily at work prospecting his ledges. His veins were not denounced, and not until February was it generally known that rich mines abounded there. In that month, L.H. Gaskill and party returned and confirmed the reports of rich placer digging in Mexican Gultch, and Mr. Gaskill stated in an interview at that time that the district would doubtless develop into a wonderfully rich quartz region. Within a week everybody in Ensenada who could get away was at the mines, and San Diego had caught the fever; in two weeks there was a population of a thousand in Santa Clara, and the great crowd of tenderfeet, dazzled by the nuggets of Mexican Gultch, entirely overlooked the rich ledges on every hand. Engineer Tyzack, Col. Allen, A.H. Butler, T.L. McCarthy, Frey & Waldrip and others went prospecting immediately in Alamo, and their rich discoveries attracted the bulk of the population to Alamo. Since then the district has been widened and lengthened, scores of ledges have been found, shafts sunk and tunnels driven, and a large and immensely rich quartz camp has been developed. Capital has been attracted, and for its age the camp is wonderfully advanced."
Between 1889 and 1908 reportedly some 217,000 ounces of gold were taken from the El Alamo-Santa Clara camp.
A few years later in 1910 the Mexican Revolution began, and for the next ten years Mexico's political instability effectively shut down the remaining mining activity at El Alamo, reducing it to the working of a few placer deposits by the remaining inhabitants. Revocation of concessions and the prohibition of foreigners owning land near the border or the coasts effectively shut down all mining activity in Baja California. In 1921 ASARCO, after six years of deliberation, sent an exploration team under the direction of Cyrus F. Tolman Jr. of Stanford University to El Alamo to evaluate the Aurora-Princesa mines. Professor Tolman, in his Preliminary Report of Conclusions from the Examination of the Aurora-Princessa Mines, Alamo, Baja California, Mexico, stated in his last paragraph: "The project as a whole is the best development proposition that has been called to my attention for the last ten years and is recommended by me." Despite this positive recommendation, ASARCO went no further with the Aurora-Princesa project. Mining activity from the 1930's through to the 1980's was sporadic and mainly confined to placer workings.
Responding to its NAFTA membership, Mexico in 1992 enacted a new Mining Law. This new law brought Mexican mining law much more in conformity with American and Canadian mining law, with the consequent renewal of mining activity interest in Mexico by American, Canadian and international mining firms. The main beneficiaries of the new law have been the States of Durango, Zacatecas and Sinaloa, with much mineral exploration activity being carried out by the Mexican companies of foreign mineral exploration firms. States such as Chihuahua, Sonora and Baja California have also benefitted from the new law.
In 1994, Tigre de Oro S.A. de C.V. of Calgary, Alberta, optioned the Sorpresa III property at El Alamo from its holder, Eduardo Boullosa. Tigre de Oro subsequently entered into an agreement in 1995 with Calais Resources Ltd., a mineral exploration company based in Chilliwack, British Columbia, which at that time was publicly traded on the Vancouver Stock Exchange (CIS:VSE). Calais Resources commenced an energetic exploration and rehabilitation programme in the San David shaft area, reporting gold assay results as high as 43.3 oz/ton from their drilling programme.