Anza-Borrego North: Wonderstone Wash

Wonderstone Wash

The chief attraction of Wonderstone Wash is wonderstone, a hydrothermally altered rock with bands of minerals such as iron and manganese in varying colors. The colors include eye-catching reds, oranges, purples, and blue-gray.

Although wonderstone is a name applied to rocks found in various parts of the world, not all wonderstone is the same. The wonderstone of Wonderstone Wash is a highly silicified sedimentary rock. The source is thought to be ancient hot springs. Fossilized particles of reed-like plants have also been found.

The area is of interest not only to geologists, miners, and weekend rock hunters, but also to anthropologists. The Cahuilla people gathered wonderstone and chipped it into arrowheads and tools. Specimens have been found at Indian sites throughout southern California, indicating its use for trade.

Wonderstone Wash itself is dry and the sand can be deep, so bring plenty of water and drive carefully.

While the wash extends deep into the mountains, you should not have to travel far to find collectable rocks. Be sure you know whether you are on private property, Indian Reservation land, or Anza-Borrego Desert State Park. It is illegal to collect wonderstone within ABDSP, and you should not collect on private property without permission.