Old Faithful Geyser, Yellowstone National Park, 1934

Yellowstone National Park, established 1872, was America's first national park. Old Faithful is the most famous and celebrated geyser in the park--and indeed the world. Members of the 1870 Washburn Expedition, who camped near this geyser, named it Old Faithful because they discovered that it erupted at frequent and regular intervals (averaging about every ninety minutes).