MEMOIR OF S. F. EMMONS 10 



This volume, containing 890 pages, was printed by the close of the year 

 and issued soon after. In it is a continuous description of the country, 

 treated geographically, beginning on the Great Plains and progressing 

 westward across the widest part of the northern Cordillera. An endeavor 

 is made to give the structural details and salient geological features lying 

 between the meridian 104 degrees west and the meridian 120 degrees 

 west, the latter being the eastern boundary of the State of California. 

 The volume of atlas maps upon which the early geology was laid down, 

 including the accompanying geological cross-sections, bears the imprint 

 of 1876. Throughout all these years Emmons worked assiduously and 

 with unfailing enthusiasm. Upon completion of the Descriptive Geol- 

 ogy, after ten years of service, Emmons resigned his position to pay 

 attention to personal matters. 



The act of Congress creating the Bureau of the Geological Survey 

 and placing it under the Department of the Interior was approved 

 March 3, 1879; three weeks later the President nominated Mr. Clarence 

 King as its tirst Director; on April 3 the Senate confirmed his nomina- 

 tion, and on May 24 Mr. King took the prescribed oath. By this legis- 

 lation all existing surveys and exploring parties ceased to have Con- 

 gressional authorization. 



One of Mr. King's first official acts w^as to secure the experienced 

 services of Mr. Emmons, and on August 4 of that year appointed him 

 Geologist in Charge of the Eocky Mountain Division, with headquarters 

 at Denver. The first two lines of his instructions read as follows : "You 

 will devote the first years of your administration of your division exclu- 

 sively to a study of the mineral wealth of the Eocky Mountains." In 

 accordance with these instructions he was requested to prepare, without 

 delay, a monograph on the Leadville region. The Geological Survey 

 having undertaken the collection of the statistics of the precious metals 

 in connection with the Tenth Census, the work was placed in charge of 

 Mr. Emmons and Dr. G. F. Becker, who were authorized to prepare the 

 statistical schedules and to employ the necessary staff of assistants. The 

 men whom they selected were for the most part mining engineers. The 

 results of the work were published in volume xiii of the series of Census 

 reports. A feature of the volume is the publication of geological de- 

 scriptions of the more important mining regions, and Mr. Emmons 

 gives, for that time, an admirable chapter entitled "Geological Sketch 

 of the Eocky Mountain Division." 



Notwithstanding the time required for the Census volume, Emmons 

 devoted the greater part of his personal attention and energy to the 

 Leadville monograph. He brought to the task a well trained mind and 



