Great Basin
noun
a region in the Western U.S. that has no drainage to the ocean: includes most of Nevada and parts of Utah, California, Oregon, and Idaho. 210,000 sq. mi. (544,000 sq. km).
British Dictionary definitions for great basin
Great Basin
noun
a semiarid region of the western US, between the Wasatch and the Sierra Nevada Mountains, having no drainage to the ocean: includes Nevada, W Utah, and parts of E California, S Oregon, and Idaho. Area: about 490 000 sq km (189 000 sq miles)