History of Oregon

The history of Oregon, a U.S. state, may be considered in five eras: geologic history, inhabitation by native peoples, early exploration by Europeans (primarily fur traders), settlement by pioneers, and modern development.

The term "Oregon" may refer to:

The history of Oregon, and of the Pacific Northwest, has received little attention from historians, as compared to other regions of the American far west.

Volcanic activity in the region has been traced to 40 million years ago, in the Eocene era, forming much of the region's landscape. In the era (the last ice age, two million to 700,000 years ago), the Columbia River broke through Cascade Range, forming the Columbia River Gorge.

The Columbia River and its drainage basin experienced some of the world's greatest known floods toward the end of the last ice age. The periodic rupturing of ice dams at Glacial Lake Missoula resulted in discharge rates ten times the combined flow of all the rivers of the world, as many as forty times over a thousand-year period.

Water levels during the Missoula Floods have been estimated at 1,250 feet (381 m) at the Wallula Gap (in present-day Washington), 830 feet (253 m) at Bonneville Dam, and 400 feet (122 m) over current day Portland, Oregon. The floods' periodic inundation of the lower Columbia River Plateau deposited rich lake sediments, establishing the fertility that supports extensive agriculture in the modern era. They also formed many unusual geological features, such as the channeled scablands of eastern Washington.

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