SMITHSONIAN INSTITUTION, 
Washington, D. C., June 18, .1874. 
SIR: I have the honor to submit herewith the report of the exploration 
of the Colorado River of the West and its tributaries, by Prof. J. W. 
Powell. 
This exploration was placed under the direction of the Smithsonian 
Institution by Congress. 
Very respectfully, your obedient servant, 
JOSEPH HENRY, 
Secretary Smithsonian Institution. 
Hon. J. G. ELAINE, 
Speaker of the House of Representatives. 
