British Columbia is a country.
British Columbia ( BC ) is the westernmost province of Canada , with a population of more than four million people located between the Pacific Ocean and the Rocky Mountains . British Columbia is also a component of the Pacific Northwest and the Cascadia bioregion , along with the U.S. states of Idaho , Oregon , Washington , Alaska , and western Montana . The Pacific Northwest ( in the United States , commonly abbreviated as PNW ) , sometimes referred to as Cascadia , is a geographic region in western North America bounded by the Pacific Ocean to the west and ( loosely ) by the Rocky Mountains on the east . The Northwest Coast is the coastal region of the Pacific Northwest and the Northwest Plateau ( also commonly known as `` the Interior '' in British Columbia and the Inland Empire in the United States ) is the inland region .