Oregon (ˈɒrɪɡən) is a state in the Pacific Northwest region of the United States. Oregon is a part of the Western United States, with the Columbia River delineating much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. The 42° north parallel delineates the southern boundary with California and Nevada. The western boundary is formed by the Pacific Ocean.
Oregon has been home to many indigenous nations for thousands of years. The first European traders, explorers, and settlers began exploring what is now Oregon's Pacific coast in the early to mid-16th century. As early as 1564, the Spanish began sending vessels northeast from the Philippines, riding the Kuroshio Current in a sweeping circular route across the northern part of the Pacific. In 1592, Juan de Fuca undertook detailed mapping and studies of ocean currents in the Pacific Northwest, including the Oregon coast as well as the strait now bearing his name. The Lewis and Clark Expedition traversed Oregon in the early 1800s, and the first permanent European settlements in Oregon were established by fur trappers and traders. In 1843, an autonomous government was formed in the Oregon Country, and the Oregon Territory was created in 1848. Oregon became the 33rd state of the U.S. on February 14, 1859.
Today, with 4.2 million people over , Oregon is the ninth largest and 27th most populous U.S. state. The capital, Salem, is the second-most populous city in Oregon, with 177,723 residents. Portland, with 652,503, ranks as the 26th among U.S. cities. The Portland metropolitan area, which includes neighboring counties in Washington, is the 25th largest metro area in the nation, with a population of 2,512,859.
Oregon is also one of the most geographically diverse states in the U.S., marked by volcanoes, abundant bodies of water, dense evergreen and mixed forests, as well as high deserts and semi-arid shrublands. At , Mount Hood, a stratovolcano, is the state's highest point.