Pinnacles National Monument, California – The earth’s movement

We leave the Pan Americana for a trip into the inland to Pinnacles National Monument. Hwy # 25 crosses the San Andreas Fault several times; we can feel the truck slightly shaking since the pavement can’t always be redone. The fault is 680 mi / 1100 km long from Mexico into northern California. The Pacific and the North American continental plates adjoin here, drifting to the north respectively the west. That usually works smoothly, but sometime the plates become entangled. When tension becomes too big, an earth quake breaks out. There are thousands every year, most of the time not even recognizable. Sometimes, like in the San Francisco earthquake of 1906, a big displacement occurs. It was measured 20 ft / 6 m. The average counter movement is 2.5 inch / 6 cm per year. The San Andreas Fault is part of the Ring of Fire surrounding the Pacific Ocean, but is one of the few areas where the continental plates adjoin on land and not under water.

The Pinnacles have actually been a volcano. Two thirds of it broke off in the area of Los Angeles 2 million years ago and drifted to the north where we can visit them today. The other third is still 195 mi / 315 km south-east. Erosion wasn’t doing nothing during this time. It created spires and pillars that gave the park its name. Many of them collapsed during the numerous earthquakes and encased a canyon nearly completely. The attraction of the park is a hike through this dark, cave-like labyrinth where sun only occasionally comes through. Firm shoes and a torch are necessary, a headlamp would be even better, for the 2.2 mi / 3.5 km long hike. Arriving on the mountain we can see the interesting pinnacles and a small reservoir that has been created in the 30s, but has never been used. After the productive rainfalls of the last weeks the reservoir overflows and brings small waterfalls and artificially created rain showers to the caves, and wet feet. We go back via Rim Trail above the gulch. The caves can temporarily be closed when the resident Indians use them.

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