The Columbia River is the major river that flows through the Pacific Northwest, forming part of the border between Washington and Oregon.

The Columbia River is the largest in the Pacific Northwest region of the U.S. It flows from the Rocky Mountains in Canada through Washington and Oregon before emptying into the Pacific Ocean. This river is crucial for the region's transportation, hydroelectric power generation, and agriculture. It also holds cultural significance for Native American tribes. The Columbia River Gorge, a scenic area along the river, is known for its breathtaking views and diverse ecosystems. It is an iconic natural feature of the Pacific Northwest, shaping the landscape and economy of the surrounding states.