Shoshone Falls, Snake River, Idaho, looking through the timber, and showing the main fall, and upper or "Lace Falls", No. 49 from the series "Geographical Explorations and Surveys West of the 100th Meridian"

From the Art Institute of Chicago record

In 1871 Timothy O’Sullivan, who had gained acclaim photographing the Civil War, was recruited by George M. Wheeler of the U.S. War Department to join a government survey of lands west of the 100th meridian. Working alongside scientists and cartographers, O’Sullivan produced large-format prints for study and official use, as well as stereographic cards for a general audience. Stereographs were made by taking two photographs of the same scene with lenses about two and a half inches apart to match the distance between human eyes. Viewed through a stereoscope, the two images combine to give the illusion of deep space. Hugh Edwards acquired several O’Sullivan works, including the complete two-volume Wheeler survey and boxed stereo set from which this image comes, as well as the photographs he made for Gardner’s Photographic Sketch Book of the War , published by Alexander Gardner.