Archeological evidence indicates that prehistoric Indians inhabited what is now Washington some 12,000 years ago. Over the centuries, two distinct cultures developed, that of the coastal Indians, who lived in settlements and engaged in fishing, food gathering, and, eventually, agriculture; and that of the Indians of the eastern plateau, who were primarily nomadic hunters. When European explorers arrived in the 18th century, the major tribes in the area were the Cayuse, Chinook, Kutenai, and Yakima.

Important dates in Washington
1775 Bruno Heceta and Juan Francisco de la Bodega y Quadra of Spain became the first Europeans to land on Washington soil.
1792 Robert Gray sailed into Grays Harbor and the Columbia River. George Vancouver surveyed the coast of Washington and Puget Sound.
1805 Lewis and Clark reached Washington and the Pacific Ocean.
1810 A British-Canadian fur-trading post was established near present-day Spokane.
1818 Britain and the United States agreed to a joint occupation of the Oregon region, which included Washington.
1846 A treaty between the United States and Britain established Washington's boundary at the 49th parallel.
1853 Congress created the Washington Territory.
1855-1858 Indian wars raged in the Washington Territory.
1883 The Northern Pacific Railroad linked Washington and the East.
1889 Washington became the 42nd state on November 11.
1909 The Alaska-Yukon-Pacific Exposition was held in Seattle.
1942 Grand Coulee Dam was completed.
1962 Century 21, a world's fair, was held in Seattle.
1964 The Columbia River Treaty of 1961 and related agreements received final approval from the U.S. and Canadian governments.
1974 Expo '74, a world's fair, was held in Spokane.
1980 Mount St. Helens volcano erupted causing 57 deaths and enormous damage in the southwestern part of Washington.
1996 Gary Locke of Washington became the first person of Chinese ancestry to be elected governor of a U.S. state.