Record level- Images from the 1968 United States Geological Survey expedition on the Green and Colorado rivers. The purpose of the expedition was to locate the camera stations and replicate the images taken by E.O. Beaman during the 1871 Powell survey of the Green and Colorado rivers. The images from the 1968 expedition were taken by Hal Stephens. Gene Shoemaker served as the expedition's project leader. These photographs were used as the basis for re-photography of the canyons of the Green and Colorado River in 1968, both sets being published in a work 'In the Footsteps of John Wesley Powell: an Album of Comparative Photographs taken in 1871-1872 and in 1968' by Hal G. Stephens and Eugene M. Shoemaker.