LETTER TO THE SECRETARY. 



Washington, July 1, 1874. 

 Sir : In accordance with your instructions, I have the lion or to present 

 for your approval the Seventh Annual Eeport of Progress of the United 

 States Geological Survey of the Territories for the fiscal year commencing 

 July 1, 1873, and ending June 30, 1874. In my letter to the Secretary 

 of the Interior, dated January 27, 1873, (Ex. Doc. No. 166,) inviting his 

 attention to some views in behalf of an appropriation for continuing 

 the survey of the Territories, and his recommendation of the same, the 

 plan of operations for the ensuing season was marked out in general 

 terms as follows : 



For the last two years the survey lias operated about the sources of t-he Missouri and 

 Yellowstone Eivers ; but the expenses of transportation, subsistence, and labor are so 

 great that it seems desirable to delay the further prosecution of the work in the 

 Northwest until railroad-communication shall be established. The Indians, also, are 

 la a state of hostility over the greater portion of the country which remains to be 

 explored. It seems desirable, therefore, to transfer the field of labor, for the coming 

 season, to the eastern portion of the Rocky Mountain range, in Colorado and New 

 Mexico. I propose to commence with the southern limit of the belt of the survey of 

 the fortieth parallel, so successfully completed under the direction of Mr. Clarence 

 King. The northern limit of the area marked out is latitude 40° 30' ; the western limit, 

 the east bank of the Green and Colorado Rivers ; the eastern limit, the one hundred 

 and third meridian west of Greenwich, extending the belt southward to the south line 

 of the United States. 



There is probably no portion of our continent, at the present time, which promises 

 to yield more useful results, both of a practical and scientific character. This region 

 seems to be unoccupied, at this time, as far as I am aware, by any other survey under 

 the Government, and the prospect of its rapid development within the next five years, 

 by some of the most important railroads in the West, renders it very desirable that its 

 resources be made known to the world at as early a date as possible. 



In accordance with the recommendation of the Secretary of the In- 

 terior, an appropriation of $75,000 was made for the systematic survey 

 of Colorado, and, at as early a date as the season would permit, the 

 party reached Denver. This place formed our starting-point for the 

 various portions of the territory which had previously been marked out 

 for the season's work. Early in the winter, the area to be surveyed in 

 Colorado was divided into three districts, and a preliminary map was 

 constructed, based on the land-surveys of those portions concerning 

 which there was any definite knowledge. We found that none of the 

 existing maps were of any great service in the more elevated portions 

 of Colorado. The area to be surveyed comprised the eastern portion of 

 the mountainous part of Colorado, and it was separated into three dis- 

 tricts : North, Middle, and South districts. 

 1 G s 



