Truckhaven Rocks, Santa Rosa Mountains

  ANZA-BORREGO NORTH : GEOLOGY AND MINING

Among the striking geological features of Anza-Borrego North are the mountains (the Santa Rosa Mountains and San Ysidro Mountains) and the Borrego Badlands.

The major faults across Anza-Borrego north, the Coyote Fault and the Clark Fault, have played a major role in the shaping of the land. These faults are part of the San Jacinto Fault Zone, a branch of the San Andreas Fault.

Mining has attracted people to the Santa Rosas for as long as there have been people here. The Cahuilla went to Wonderstone Wash to collect stones for various purposes including the making of arrowheads. At the head of Rockhouse Canyon, the Nichola Swartz mine is said to have yielded $10,000 in gold nuggets, a lot of money at the time. The Calcite Mine, perhaps the best-known mine in the Santa Rosa Mountains, was opened in World War II.

Hikers through Palo Verde Wash, often on the way to the Natural Rock Tanks near Smoke Tree Canyon, taking the Wonderstone Trail past the entrance to the Moly Mine. Why it is called Moly and what was mined there aren't known for sure.