Geology
The diverse geology that surrounds the Sierra Nevada Mountain Range comes from a symphony of ice, wind, fire and time. From Tehachapi Pass up north to Mount Lassen, the Sierra Nevada Mountain Range runs 400 miles long and 50 to 80 miles wide and lies along the eastern side of the highest mountain in the lower 48 states, the 14,494-foot Mount Whitney.
Compared to other mountain ranges, the Sierra Nevada Range is new. Ridges in the heart of the Eastern Sierra that average 12,000 feet in elevation is only one example of the geological splendor of the area. This beautiful region of California contains as much fascinating geology as it does outdoor recreation.
Were you to visit 500 million years ago you'd need to pack a boat, as much of western California lay under the Pacific's waters. As mud, silt and sand deposited on the ocean floor they solidified into sedimentary rock.
Over the past millions of years subterranean forces have pushed the land upward out of the ocean only to have the sea reclaim it. Volcanic eruptions covered the region, pushed the sedimentary slabs and contributed to the rock masses that make the Sierra Nevada so distinctive.
The area surrounding Mammoth Mountain is geothermally and seismically active. Mono Basin contains a chain of young volcanoes (the youngest in the country), and one of the oldest bodies of water in North America (Mono Lake).
Glaciers formed the U-shaped valleys and carried large boulders in its flows. Glacial moraines can be found throughout the area.
Glacier activity hasn't ended as the Sierra Nevada contains the southernmost active glacier in the country, Palisade Glacier.