Map of the Black Hills of Dakota, from explorations made in 1873. W.P. Jenney, Engineer of Mines, in charge. H. Newton, Engineer of Mines, geologist. V.T. M'Gillycuddy, M.D., topographer. H.P. Tuttle, A.M., astronomer. Drawn by Emil Mahlo. Dept. of the Interior, U.S.G. and G. Survey, J.W. Powell, in charge. Geology of the Black Hills by Henry Newton, E.M. (Julius Bien, Lith. New York, 1879)