Archaeological evidence documents the presence of people in Oregon and Washington for over 12,000 years. Hunters following the big game of the Pleistocene camped along the large, inland lakes that occupied much of eastern Oregon. Archaeological finds from sites such campsites as Fort Rock Cave, dated at 12,500 years ago, document this early history. More commonly, scattered Clovis points - uniquely fluted Paleo-Indian spear points - at such locations as the Dietz site, attest to the presence of these early hunters.
By 8,000 years ago, environmental changes associated with the ending of the ice ages and the beginning of the Holocene brought about the development of the Archaic hunting-gathering tradition in the Pacific Northwest. This way of life persisted throughout Oregon and Washington until Europeans came to the continent a few hundred years ago, leaving a unique record of such pronounced economic stability.
Through this long, 8,000-year period, significant environmental differences led to different customs within the region. In the West, and especially along the Columbia River, the rich, temperate environment fostered populous, sedentary villages based in large part on fish and other abundant and predictable resources from the rivers and the sea.
This subsistence base extended upstream along the Columbia River and its tributaries, on the high and dry Columbia Plateau. These prolific fisheries drew tribes from many areas, allowing local tribes to control major centers for regional trade. People living in the arid southeast part of Oregon roamed across great distances in an annual round to collect and store foods and materials necessary for survival.
European explorers came in ships along the coast, bringing devastating diseases to the Native population by the late 18th century. Lewis and Clark reached the Columbia River, near the present city of Portland, in 1805. Fur traders followed and brought with them a struggle among European countries for control over the Pacific Northwest.
In 1846, the region became an American territory, and settlement in the temperate and fertile Willamette Valley of northwest Oregon was well underway. Many pioneers braved the hazards of the Oregon Trail for the promise of wealth in the new land. In the early 1850s, the discovery of gold in southwestern Oregon, as well as the passage of the Oregon Donation Land Claim Act, brought a new flood of immigrants.
Gold discoveries in eastern Oregon and Washington by the 1860s led to immigration and settlement in those regions. Bloody conflicts ensued and the push to open lands to settlement resulted in the placement of surviving Native peoples on reservations. An estimated precontact population of over 180,000 people was reduced to less than 40,000, undermining indigenous economies.