State, northwestern U.S. Area: 97,047 sq mi (251,351 sq km). Pop. (2009 est.): 3,825,657. Capital: Salem. Oregon lies on the Pacific Ocean and is bordered by Washington, Idaho, Nevada, and California. The Columbia River forms its northern boundary; the Snake River is its upper eastern boundary. The Cascades Range, with Mount Hood, is in western central Oregon. First sighted by Spanish explorers, it was visited by Francis Drake in 1579 and by James Cook in 1778. The area was inhabited by many Native American peoples when in 1792 Capt. Robert Gray explored the Columbia River, giving the U.S. a claim to the region. The river's mouth was reached by the Lewis and Clark Expedition in 1805. The first white settlement was founded at Astoria in 1811 by the fur trader John J. Astor. Settlement of the area accelerated from c. 1843 with mass migration over the Oregon Trail. It was part of the Oregon Territory and was admitted to the Union as the 33rd state in 1859. The state's economy is dependent on its forests, farms, and livestock. Salmon and shellfish are the bases of the fishing industry. Centres of population, arts, and education are Portland, Eugene, and Medford.