The rugged Santa Rosa Mountains rise up from the desert floor northwest of the Salton Sea, in the extreme south-central part of California. Part of the Peninsular Ranges, the Santa Rosa Mountains stretch for nearly 40 miles in a northwest-southeast direction. The Santa Rosas are dominated by three peaks, Toro Peak and Santa Rosa Mountain in the northwest part of the range and Rabbit Peak in the southeast part. Toro Peak is the highest peak in the Santa Rosas, rising to 8717 feet. The mountains decrease in elevation to the southeast, eventually petering out into a series of low hills just west of the Salton Sea. The Santa Rosas are bounded on the east and west by the Coachella Valley and Clark Valley, respectively. The range is separated from the adjacent San Jacinto range to the northwest by Palm Canyon. The southern part of the range merges with the seared wasteland known as the Borrego Badlands. The town of Borrego Springs lies a scant 12 miles southwest of the Santa Rosas.
The Santa Rosa Mountains have always stood on the periphery of events in California. Even today, the area is remote and fairly inaccessible. In 1774, a Spanish expedition led by Juan Bautista de Anza passed through Borrego Springs on its way to San Gabriel Mission, near present day Los Angeles. But for the most part, people and events have by-passed the Santa Rosas.
The mountains have an air of mystery about them. For many years, persistent rumors of rich gold-bearing pockets in the Santa Rosas have circulated around the mining camps of southern California. Indeed, a few of these have been discovered. The area also contains numerous Pre-Columbian archeological sites including camp sites, stone rings, and ancient Indian trails. Many legends have come down to us concerning the activities of these early Indians. One of the most intriguing legends is that of a lost emerald mine worked for many years by the local Indians.
In the 1940's, a mining engineer named Marshal South got wind of the legendary emerald mine from an old Indian living in Hermosilla. The two formed a partnership and began prospecting the Santa Rosa Mountains. Using Rockhouse Canyon as their base camp, Marshal South and the old Indian scoured the mountains in search of the emerald deposit. Although they never located the mine, they did find a small fragment of emerald in one of the many steep canyons that cut the flanks of the Santa Rosas. The emerald was found mixed with beryl float at the bottom of the canyon.
The Santa Rosa Mountains harbor no major metalliferous deposits, either precious or base-metal. The Santa Rosas also apparently lack any major gem-producing pegmatite bodies. The nearest mining districts lie 35 miles southwest of the Santa Rosas. The Mesa Grande District was located between present-day Lake Henshaw and the little town of Mesa Grande. During the late 1880's, rich deposits of gold ore were discovered northeast of Mesa Grande, but the veins quickly gave out. The Julian District is located about 15 miles southeast of Mesa Grande. It includes the