Old Faithful was named by the Washburn Expedition of 1870, who explored the area that would later be called Yellowstone. Members of the expedition entered the Upper Geyser Basin after traveling down the Firehole River and saw the geyser, which they called Old Faithful because of the regularity with which it erupted. Geysers like Old Faithful are only formed under specific conditions, making them relatively rare. Magma under the Earth’s surface superheats pockets of underground water,  ...