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: * Oregon Country, a large region explored by Americans and the British (and generally known to Canadians as the Columbia District); * Oregon Territory, established by the United States two years after its sovereignty over the region was established by the Oregon Treaty; and * Oregon, a U.S. state since 1859