R. Robinson,People watching Old Faithful erupt from geyser cone, Yellowstone National Park, Wyoming, 1948.
William Bell, Grand Canyon of the Colorado, mouth of Paria Creek, looking west from plateau, 1872.
Source: National Archives and Records Administration
William Henry Jackson, The U.S. Geological and Geophysical Survey of the Territories, conducted by Hayden, en route with pack train upon the trail between the Yellowstone and East Fork Rivers, Yellowstone National Park, Wyoming, 1871.
Ansel Adams, The Tetons and the Snake River, Grand Teton National Park, Wyoming, 1942.
Source: National Archives and Records Administration, Records of the National Park Service