Oregon is a state in the Pacific Northwest region of the United States. Oregon is a part of the Western United States, with the Columbia River delineating much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. The 42° north parallel delineates the southern boundary with California and Nevada. The western boundary is formed by the Pacific Ocean.

The Snake River is a major river in the interior Pacific Northwest region of the United States. About 1,080 miles (1,740 km) long, it is the largest tributary of the Columbia River, which is the largest North American river that empties into the Pacific Ocean. Beginning in Yellowstone National Park, western Wyoming, it flows across the arid Snake River Plain of southern Idaho, the rugged Hells Canyon on the borders of Idaho, Oregon and Washington, and finally the rolling Palouse Hills of southeast Washington. It joins the Columbia River just downstream from the Tri-Cities, Washington, in the southern Columbia Basin.