The Yellowstone Caldera, also known as the Yellowstone Plateau Volcanic Field, is a Quaternary volcanic field, caldera complex, and volcanic plateau spanning parts of Wyoming, Idaho, and Montana. It is driven by the Yellowstone hotspot and lies largely within Yellowstone National Park. The field comprises several overlapping caldera structures, multiple lava domes and resurgent domes, and numerous bimodal lavas and tuffs of basaltic and rhyolitic composition, originally covering about 17,000 km2 (6,600 mi2).