LOWER FALLS OF THE YELLOWSTONE, Yellowstone National Park If there were no geysers or other objects of interest in the Yellowstone, the spectacular Grand Canyon of the Yellowstone River alone would warrant national park status. The canyon has been cut through richly colored volcanic rock, largely yellow in hue but containing all the colors of the rainbow, its sides broken by vertical ledges and isolated pinnacles. Through it rushes the river, still cutting, and forming two great waterfalls—the Upper and Lower Falls of the Yellowstone. Down in the canyon are at least three small geysers and other steam vents. Nathaniel Langt ford's entry in his diary for August 31, 1870, tells of the discovery of the canyon by the famous exploring parry and says "It lingers in my memory like the faintly defined outlines of a dream."