High Quality Content by WIKIPEDIA articles! The Interior Plateau comprises a large region of central British Columbia, and lies between the Cariboo and Monashee Mountains on the east, and the Hazelton Mountains, Coast Mountains and Cascade Range on the west. The continuation of the plateau into the United States is known there as the Columbia Plateau. The Interior Plateau is not part of the Interior Mountains, a huge area that constitutes most of the northern two thirds of the Canadian province of British Columbia between the Coast Mountains, Rocky Mountains and the various small ranges on the inland lea of the Coast Mountains between the Bulkley Ranges and the Bella Coola River. Physiographically, the Interior Plateau is a section of the larger Northern Plateaus province, which in turn is part of the Intermontane Plateaus physiographic division.