A rainbow arises colorfully in the mists above the upper falls in the Grand Canyon of Yellowstone National Park

waterfall water falls upper lower mist spray yellowstone national park yellowstone national park whitewater waterfalls canyon colorful river raging thunderous montana wyoming idaho foam flowing flow rapids brink scenic geological super volcano volcanic cascade grand canyon of yellowstone erosion yellowstone river limestone super heated steam steamy environment touring travel tourist landmark vacation visitors holiday conservation environmental global warming