Washington ( ) is a state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute. It was admitted to the Union as the 42nd state in 1889. The United States Census Bureau estimated the state's population was 6,549,224 as of 2008.

The state is named after George Washington, the 1st President of the United States. It is the only U.S. state named after a president. Residents are called "Washingtonians" (emphasis on the third syllable, pronounced as tone). Washington is often called Washington State or the State of Washington to distinguish it from the District of Columbia. However, Washingtonians always refer to the state simply as "Washington" while usually referring to the nation's capital as "Washington D.C." or simply "D.C."

Geography

Washington is the Northwestern-most state of the contiguous United States. Its northern border lies mostly along the 49th parallel, and then via marine boundaries through the Strait of Georgia, Haro Strait and Strait of Juan de Fuca, with the Canadian province of British Columbia to the north. Washington borders Oregon to the south, with the Columbia River forming most of the boundary and the 46th parallel forming the eastern part of the southern boundary. To the east Washington borders Idaho, bounded mostly by the meridian running north from the confluence of the Snake River and Clearwater River (about 116°57' west), except for the southernmost section where the border follows the Snake River. To the west of Washington lies the Pacific Ocean. Washington was a union territory during the civil war, though never actually participated in the war.

Washington is part of a region known as the Pacific Northwest, a term which always includes at least Washington and Oregon but may or may not include Idaho, western Montana, northern California, and part or all of British Columbia, Alaska, and the Yukon Territory, depending on the speaker or writer's intent.

The high mountains of the Cascade Range run north-south, bisecting the state. Western Washington, west of the Cascades, has a mostly marine west coast climate with relatively mild temperatures, wet winters, and dry summers. Western Washington also supports dense forests of conifers and areas of temperate rain forest. In contrast, Eastern Washington, east of the Cascades, has a relatively dry climate with large areas of semiarid steppe and a few truly arid deserts lying in the rainshadow of the Cascades; the Hanford reservation receives an average annual precipitation of between six and seven inches (178 mm). Farther east, the climate becomes less arid. The Palouse region of southeast Washington was grassland that has been mostly converted into farmland. Other parts of eastern Washington are forested and mountainous.