Archive - Joshua Tree National Park

Each Sunday we present a notable item from our archives. This EPOD was originally published July 6, 2003.

Provided and copyright by: Jacob Sears
Summary authors & editors: Jacob Sears; National Park Service

The photo above was taken in Joshua Tree National Park in California. The plant in the foreground is a California Barrel Cactus (Ferocactus cylindraceus). Joshua Tree Park consists of two somewhat distinct desert ecosystems. To the west is the lower (below 3,000 ft or about 915 m) and hotter Colorado desert, and to the east is the slightly higher and more moist Mojave Desert. Geologists believe that the face of this fascinating landscape was formed more than 1 million years ago. In more recent times (past 10,000 years or so), flash floods have washed away soil and sand layers, exposing boulders which had been eroded tens of thousands of years earlier. Powerful floodwaters piled the boulders on top of another, creating the impressive rock piles we see today (background).

Related Links:

• Joshua Tree National Park
• Geology of the Park
• Self-Guided Geologic Tour in Joshua Tree National Monument
• Barrel Cactus

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