Europe and Africa have the Atlantic Ocean as their western border.
Pacific Ocean
Pacific Ocean
Pacific Ocean
the ocean that forms the western border of the US is the Pacific Ocean
The pacific ocean.
The Atlantic Ocean borders Europe to the west, not a country.
The Arctic Ocean straddles the earth's northern pole. No continent has the Arctic Ocean as a western border; two or three continents have the Arctic Ocean as a northern border: North America and Eurasia (or Europe and Asia).
Mediterranean Sea
Europe's western Ocean is the North Atlantic.
Assuming your mean Washington State, it would be the Pacific Ocean
The Columbia River.