Washington, D. C , March 28, 1885. 

 Sir: I have the honor to submit for publication a memoir on Lake 

 Lahontan by Mr. I. C. Russell. 



The principal work of my Division has been the investigation of the 

 Quaternary lakes of the Great Basin. In this investigation Mr. Russell has 

 been my principal assistant since the year 1880. During the first season 

 he accompanied me in the field for the purpose of familiarizing himself with 

 the methods of research which had been developed in the course of the 

 earlier work, but in subsequent years he was assigned independent districts. 

 His report on the most important of these is communicated in the pres- 

 ent volume. 



After the completion of his field work, I visited some of the more in- 

 structive localities of the Lahontan basin and repeated his observations. I 

 am thus familiar not only with his methods but with some of the principal 

 facts which he discusses, and am enabled from personal knowledge to char- 

 acterize his work as accurate and thorough. 



Very respectfully, your obedient servant, 



G. K. GILBERT, 

 Geologist in Charge, Division of the Great Basin. 

 Hon. J. W. Powell, 



Director U. S. Geological Survey. * 



