The river flowing between Washington and Oregon is the Columbia River.
Well, there is a bit of the Columbia river, the snake river, AND spokane river. There may be thers but I know these ones are there.
1805
Lewis and Clark explored Missouri River, and Columbia River.
Washington
Magdalena-river
Columbia River
Potomac River
The Columbia River is the major river in Washington.
Columbia river
Columbia River
The Columbia River originates in British Columbia
The Columbia River borders most of the length between Washington & Oregon.
The Columbia River.
The Columbia river
Lewis and Clark explored the Columbia River.
what is the list of dams on the columbia river