An arm of the Pacific Ocean in northwest Mexico separating Baja California from the mainland. CA a state in the southwest of the US, next to the Pacific Ocean, whose main cities include San Francisco and Los Angeles. State (pop., 2000: 33,871,648), western U.S. Lying on the Pacific Ocean, it is bordered by Mexico and the U.S. states of Oregon, Nevada, and Arizona. California is the largest state in population and the third largest in area (158,647 sq mi [410,895 sq km]), extending about 800 mi (1,300 km) north to south and 250 mi (400 km) east to west. Its capital is Sacramento. Within 85 mi (137 km) of each other lie Mount Whitney and Death Valley, the highest and lowest points in the 48 contiguous states. It was inhabited originally by American Indians. The first European coastal expansion took place in 1542-43 when Juan Cabrillo established a Spanish claim to the area. The first mission was established by Junipero Serra at San Diego in 1769. The region remained under Spanish and, after the 1820s, Mexican control until it was taken by U.S. forces in the Mexican War and ceded to the U.S. by the Treaty of Guadalupe Hidalgo in 1848. Though settlement had begun by the U.S. in 1841, it was greatly accelerated by the 1848 gold rush. California was admitted to the Union in 1850 as a nonslavery state under the Compromise of 1850. Its already expanding population grew immensely in the 20th century. It has the largest economy of any U.S. state. It has suffered severe earthquakes, most destructively those of San Francisco in 1906 and 1989 and Los Angeles in 1994. Baja California Lower California Baja California Norte Baja California Sur California Gulf of California University of California Institute of Technology California Institute of the Arts California poppy Regents of the University of California v. Bakke