Washington, D. C, March 1, 1880. 

 Sir : I have the honor to transmit herewith the manuscript of the 

 Report on the Geology and Resources of the Black Hills of Dakota, placed 

 in my hands for revision. 



I am, with respect, your obedient servant, 



G-. K. GILBERT. 

 Maj. J. W. Powell, 



In charge U. S. G. and G. Survey, B. M. B., Washington, D. C. 



m 



