The 1872 Act of Congress which created Yellowstone National Park set aside two million acres in Wyoming Territory as a public “pleasuring-ground” whose natural beauties and wonders were to be preserved for posterity and protected from exploitation or private gain. Thus was born the nation’s first national park, destined to become the model for others all over the world. Yellowstone had been the home of Native Americans for centuries before the first white explorer, John Colter, passed through the region in 1807. Colter’s stories of boiling geysers and other natural wonders were simply not believed, and the accounts of most other explorers in the next half century were similarly discredited. but after the Civil War, successive government expeditions made systematic explorations of the area and brought back information whose authenticity could not be doubted. The Folsom-Cook expedition (1869) and the Washburn-Langford-Doane expedition (1870) yielded detailed descriptions of Yellowstone’s geysers’, hot springs, waterfalls, mountains and forests, while the photographs of William H. Jackson and the paintings of Thomas Moran, both of whom accompanied the Hayden expedition in 1871, provided a compelling visual record. Railroads had now made the region more accessible and by the 1880s it had become a mecca for tourists.