In the footsteps of John Wesley Powell; an album of comparative photographs of the Green and Colorado Rivers, 1871-72 and 1968

Stephens, H.G., and Shoemaker, E.M., 1987, In the footsteps of John Wesley Powell; an album of comparative photographs of the Green and Colorado Rivers, 1871-72 and 1968: Boulder, Colo., Johnson Books, and Denver, The Powell Society, 286 p.