

SIXTH ANNUAL REPORT 



OP THE 



ONITED STATES GEOLOGICAL SURVEY 



OF 



THE TERRITORIES,/ /fru^ttJ 



EMBKACIKG 



PORTIONS OF MONTANA, IDAHO, WYOMING, AND ITTAH ; 

 BEING A REPORT OF PROGRESS OF THE EX- 

 PLORATIONS FOR THE YEAR 1S72. 



BY 



F. V. HAYDEN, 



JJnITED ^TATES jaEOLOGIST. 



CONDUCTED UNDER THE AUTHORITY OF THE 

 SECRETARY OF THE INTERIOR. 



[.EC 271982 



WASHINGTON 



t/8RARlE%. 



GOVERNMENT PRINTING OFF I 



1873. 



