In 1873 Timothy O'Sullivan led a splinter group from Lieutenant George Wheeler's geological expedition to Zuni Pueblo in northeast Arizona and to the pre-Columbian cliff dwellings known as the White House Ruins at Cañon de Chelle, mostly dating from the eleventh century. O'Sullivan was one of the first people to photograph the structures nestled in the canyon wall. Above the architectural forms, the monumental striated rock formation hovers illogically where the sky should be. O'Sullivan, photographing from a great distance, conveyed the sense of overwhelming scale. Along with the two tiny figures standing at the left center, the photograph's original caption, which identifies the location as: "In a Niche 50 feet above Present Cañon Bed," provides a measure of scale.