California's mountains include many of the highest peaks in the country, including Mount Whitney, the highest summit in the contiguous United States. The state is home to numerous mountain ranges, including the many Pacific Coast Ranges and the majestic Sierra Nevada.
The Sierra Nevada formed 200 million years ago from the cooling of a massive upwelling of molten granite known as a batholith. The hard rocks of the Sierra Nevada are hostile to most forms of plant life, but the range is home to the Sequoias, massive redwood trees that are the largest living things on Earth.
Although the range is usually associated mostly with Oregon and Washington, the Cascade mountains also extend into the Northeast corner of California. The Californian part of the Cascades is home to Mount Shasta, a gorgeous summit that is the second tallest in the range after Washington's Mount Rainier. Mount Shasta is not only a tall mountain, it is also massive in terms of pure volume. The peak is the tallest by far in its immediate area, making its snowy summit visible from distances of over 100 miles.
California's Cascade mountains rub shoulders with the coastal Klamath mountains. The Klamath range is very unusual geologically, as the subduction zone at the Western edge of North America's tectonic plate has significantly deformed the rocks in this region over millions of years. Thompson Peak, a craggy granite mountain whose sides were carved by an ancient glacier, is the highest summit in the range.