Oregon (ORR-ih-gən) is a state in the Pacific Northwest region on the West Coast of the United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. The parallel 42° north delineates the southern boundary with California and Nevada. Oregon was inhabited by many indigenous tribes before European traders, explorers, and settlers arrived. An autonomous government was formed in the Oregon Country in 1843 before the Oregon Territory was created in 1848.