Yosemite in Depth: Geology

Yosemite Valley provides a spectacular example of the power of geologic activity. It has been referred to as "the global masterpiece of those awesome artists: earthquake, glacier, wind, and water." But how did these artists sculpt this masterpiece?

Geology

The question about Yosemite’s origin proved difficult to answer. Controversy raged over several theories. Josiah D. Whitney, director of the California State Geological Survey in the 1860s, theorized that a cataclysmic event caused the valley floor to drop. He believed that this left behind a valley with steep walls, Yosemite Valley.

John Muir had a different idea. He developed his theory after discovering remnants of glacial action and a remaining glacier in the high Sierra. John theorized that these were the remains of glaciers that once gouged out Yosemite Valley.

In 1913, geologist Francois Matthes began a field study of Yosemite Valley’s origins. His book, Geologic History of the Yosemite Valley, was printed in 1930. He confirmed John Muir’s hypothesis of glacial formation but altered many of its details. More recently, geologist King Huber updated the geologic information concerning Yosemite’s origins with more current data (The Geologic Story of Yosemite National Park, 1989).

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