Discover California and Explore the Geodiversity of El Capitan in Yosemite National Park
- Wayne Munday
- Jul 20, 2025
- 2 min read
Updated: Dec 20, 2025
Yosemite National Park, a UNESCO World Heritage Site spanning over 759,000 acres in California’s Sierra Nevada, is a living laboratory of Earth’s geological history. At its heart, El Capitan rises 2,307 meters above sea level, a massive granite monolith sculpted by tectonic forces, the Sierra Nevada Batholith, and Pleistocene glaciers. From Jurassic-era subduction of the Farallon Plate to contemporary exfoliation and weathering processes, Yosemite’s landscapes reveal deep-time geological stories. Beyond its natural grandeur, El Capitan gained global attention when Alex Honnold achieved the first free solo climb in 2017 and serves as a dramatic backdrop for Netflix’s Untamed. Yosemite offers unparalleled opportunities for hiking, climbing, photography, and immersive exploration of North America’s iconic wilderness.
Over the last 20 million years the once buried Sierra Nevada Batholith has been slowly uplifted as tectonic forces drove it upwards. Yosemite National Park lies within the central Sierra Nevada and is the largest fault-block mountain range in the United States of America and tilts gently westward while its eastern escarpment rises steeply due to active faulting.
As the overburden or layers of soil and rock above the Sierra Nevada Batholith were stripped away the underlying granite expanded and fractured from changes in pressure creating vertical joints and exposure to the on-going process of exfoliation or physical weathering.
Although pressure release is the main driver of exfoliation other factors such as temperature changes causing thermal expansion and contraction, freeze-thaw cycles and chemical weathering have also played a role in shaping Yosemite’s many domes, cliffs and instances of rockfall.
During the Pleistocene Epoch between 2.6 million – 12,000 years ago glacial ice advanced through the rising Sierra exploiting these fractures to scour and polish the granite bedrock by transforming once V-shaped river valleys into classic U-shaped glacial canyons such as Yosemite Valley a broad, flat-floored corridor flanked by the polished granite walls of Half Dome and El Capitan. Glacial ice not scoured the landscape it left behind moraines, striations and erratic's found today in the high country of Yosemite.
Though Yosemite’s Ice Age glaciers have long since vanished a few icy remnants remain. The Lyell and Maclure Glaciers studied by John Muir back in the 19th century are now in rapid retreat. The Lyell Glacier, in fact, no longer flows and has lost over 90% of its volume.
Yosemite National Park and especially the iconic granite monolith of El Capitan stands as a breathtaking monument to Earth’s deep-time story. Shaped by the subduction of the Farallon Plate, the rise of the Sierra Nevada Batholith and sculpted by glaciers and weathering over millions of years, this landscape is must-see wilderness destination.