California's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east; and from the redwood–Douglas fir forests in the northwest to the Mojave Desert in the southeast. The Central Valley, a major agricultural area, dominates the state's center. Though California is well-known for its warm Mediterranean climate, the large size of the state results in climates that vary from moist temperate rainforest in the north, to arid desert in the interior, as well as snowy alpine in the mountains.
The state was named for the Colorado River, which Spanish travelers named the Río Colorado for the ruddy (Spanish: colorado) silt the river carried from the mountains. The Territory of Colorado was organized on February 28, 1861, and on August 1, 1876, U.S. President Ulysses S. Grant signed Proclamation 230 admitting Colorado to the Union as the 38th state. Colorado is nicknamed the "Centennial State" because it became a state a century after the signing of the United States Declaration of Independence.