The Sierra Nevada
The snow-capped peaks running down the center of this image belong to the Sierra Nevada mountains of California and Nevada.
The Sierras are about 650 kilometers (400 miles) long; they are bounded by the Central Valley of California to the West and the Great Basin of Nevada to the East. They are a popular tourist destination; Lake Tahoe, Yosemite and Sequoia-Kings Canyon National Parks are found here.
The region is famous for its giant sequoia (Sequoiadendron giganteum), the largest tree by volume in the world. These massive trees are adapted to fire, requiring sunlight to germinate their seeds.
Fire suppression in the Sierras has led to increased competition from other species, such as white fir, and declines in Sequoia populations. Prescribed burns, or intentionally-set fires, are sometimes used to re-create the natural fire regime and restore this important species to its former status.
The Sierras also provide habitat for California spotted owls. Like their conspecifics (members of the same species) the Northern spotted owls, the California variety also prefers old-growth forests.