Final answer:
The Columbia Plateau is the region on the map of Washington State, characterized by its volcanic geology and location between the Cascades and the Rocky Mountains.
Step-by-step explanation:
The Columbia Plateau is the region shown on the provided map of Washington State. This is a large igneous province dominated by Cenozoic volcanic rocks and is a product of the Yellowstone Hotspot. The Columbia River Gorge, for example, is a significant feature within this region. The Columbia Plateau extends between the Cascades and the Rocky Mountains and is known for its diverse geologic features, including the effects of massive volcanic eruptions.