Yosemite at a Glance:
Geology

Yosemite's geology is linked to the origin of the Sierra Nevada mountain range, which stretches along California's eastern flank. What is now the Sierra Nevada and the Central Valley of California was once under water!

Geology
Waterfalls

Sierra Nevada Uplift

Large amounts of sand, silt, and mud eroded from ancient mountain ranges surrounding the ancient sea and settled to the sea floor in layers, eventually becoming sedimentary rock. Great forces deep inside the earth’s crust warped these sedimentary rock layers, lifted them above sea level, and folded them into a mountain range extending northeast to southwest.

These forces changed the sedimentary rock into metamorphic rock. Metamorphic rocks can still be found along Highway 140 in the El Portal area. As the mountains rose, molten rock began to form beneath them. The molten rock eventually cooled and solidified into the granitic rocks we see in Yosemite today. Over millions of years, weathering and erosion stripped away the overlying metamorphic rocks and created a landscape of rolling hills, broad valleys, and meandering streams.