The existence of gold in the northeastern part of La Baja has long been known. Old maps show the general location of gold-bearing districts in that territory lying in a direct line between San Diego and the mouth of the Colorado River, and due east of the Ensenada.
In 1870 gold placers were discovered in the San Rafael valley, resulting in an excitement which attracted many immigrants to La Baja, and caused a regular stage-line to be run thither from San Diego. It brought corresponding disadvantages in the way of incentives to depredations by Indians and bandits.
In “Peninsular California,” Mr. Charles Nordhoff wrote as follows: ” There are at several points on the peninsula considerable placer and quartz deposits promising well, and there have been lately discoveries of copper deposits in the northern part, believed to be as rich as those on the gulf coast. The color of gold can be got in almost every gulch and ravine on the peninsula; and when the mineral resources are better known, it will probably be found that the peninsula is but an extension of the great Northern California gold-field.”
Thus the history of the past, and the forecast of the future, made by experienced intelligence, had paved the way for an enthusiastic, not to say friendly, eager reception of the announcement made in the San Diego Sun of February 28, 1890, of the discovery of marvelously rich gold fields in the Santa Clara district, some sixty miles from La Ensenada de Todos Santos. The first gold exhibited as found there was a ten-ounce nugget, which was picked up by a Mexican boy named Malendrez, searching for strayed cattle. No sooner was the news given to the outside world than it spread, or fairly leaped, like an electric thrill, all over the country. From every quarter, and from great distances, came throngs stricken with mining-fever. Those San Diego houses which dealt in articles suitable for mining and camp life, and provisions, soon found depleted their stocks of those wares.
The customhouse at Tia Juana assumed an importance never enjoyed before in all its existence, and that at Ensenada also felt strongly the impulse of the enormous immigration. Men in all walks in life left their various avocations to rush to the mines, and the district was shortly crowded with merchants, miners, ranchers, professional men and loafers, all eager to wrest a sudden fortune from the placers. The natural and inevitable results speedily ensued. The journey and sojourn were full of great discomforts; the territory was limited; supplies were very dear, and scarce at any price; very many people had started for the mines with very little money, to arrive penniless, trusting to the resources of the spot to rehabilitate their purses. Then to crown all, the placers became exhausted. All these difficulties and drawbacks did not fail to produce a tremendous outcry of wrath and disappointment and the malcontents inveighed bitterly against the discoveries as fraudulent or mythical which they were not. Meanwhile, rich ledges of gold-quartz had been die covered, and men of means who had gone thither to investigate the placers found other sources of mining richness less immediate of result, but more stable. Thus money was in-vested, mills and other improvements of advanced mining methods constructed, and there has sprung up in the mining district a flourishing little town, Alamo, while work is steadily advancing and the mining industry seems to be here firmly established upon a solid basis. These mines are situated in the Santa Clara range of mountains, seventy miles northeast of Ensenada, and 150 miles southeast of San Diego. The mineral belt, as far as developed, extends from two miles south of Camp Alamo, near the base of Tomasa Mountain, ten miles northwesterly, by some two miles wide, several hundred quartz locations having been made therein. The general character of the country is mesa land, over which wagons can be driven almost at discretion, the surface covered with sagebrush, cedar, and juniper, with some manzanita and scrub oak.
The country rock is generally granite and porphyry. Large porphyry dikes stand out boldly, being traceable for miles from north to south. The quartz veins, also traceable for long distances, run parallel to the dikes, their strikes being northwest and southeast, and the dip being an average of seventy-five degrees to the south. The average width is three to five feet, with a maximum of seven feet. The veins are sometimes encased wholly, in granite on one side and porphyry on the other, being well defined. The quartz is that known as “sugar quartz,” from its resemblance to loafsugar, and easily crushable “ribbon rock,” mostly free from base metals. The gold is generally distributed in fine particles, much of the richest ore showing no gold visible to the naked eye. Several locations frequently are made on the same vein, and on all such pay rock has been discovered. This is important, as showing the veins are continuous for a long distance; with pay rock their entire length, which conditions are unusual in other mineral-bearing regions. The greatest depth as yet reached is forty-five feet with short drifts toward either side to determine the direction and the dip. At that depth, most of the veins show increased strength, in some cases widening to eight and nine feet, and becoming more vertical, with perfect walls; the enclosing rock indicates increased width of veins at lower depth. In the majority of cases more or less water is found at from fifteen to forty feet deep, which usually indicates deep fissures, or continuous veins to great depths. For most of the mines pumping machinery will be required before any great depth can be reached.
The country surrounding the mines is better watered than most other portions of the peninsula, the water being pure and cool. Among the most important mines are the Elsinore, Asbestos, El Paso, Ulises, Centipede, Telemaco, Grandota, Graude, Encantada, Rattlesnake, St. David, Montezuma, Princesa, Cocinero, Aurora, Scorpion, Arabella, Lavina, Sunrise, and Rain-bow. Some of the most important mining companies are the International, the El Paso, the Independencia, and the Alamo.