238 
Prof. Hayden's Explorations . 
[April, 
VI. THE UNITED STATES 
GEOLOGICAL AND GEOGRAPHICAL SURVEY 
OF THE TERRITORIES.— EXPLORATIONS in 1876. 
By Prof. F. V. Hayden, Geologist in Charge. 
S HE various parties composing the United States Geo- 
logical and Geographical Survey of the Territories 
commenced their field-work in August. Owing to 
the evidences of hostility among the northern tribes of 
Indians it was deemed most prudent to confine the labours 
of the Survey to the completion of the Atlas of Colorado. 
Therefore the work of the season of 1876 was a continua- 
tion of the labours of the three preceding years, westward, 
finishing the entire mountainous portion of Colorado, with 
a belt of 15 miles in width of northern New Mexico, and a 
belt 25 miles in breadth of eastern Utah. Six sheets of the 
Physical Atlas are now nearly ready to be issued from the 
press. Each sheet embraces an area of over 11,500 square 
miles, or a total of 70,000 square miles. The maps are 
constructed on a scale of 4 miles to 1 inch, with contours 
of 200 feet, which will form the basis on which will be 
represented the geology, mines, grass, and timber lands, 
and all lands that can be rendered available for agri- 
culture by irrigation. The areas of exploration the past 
season are located in the interior of the continent, far 
remote from settlements, and among the hostile bands of 
Ute Indians that attacked two of the parties the previous 
year. 
The point of departure the past season was Cheyenne, 
Wyoming Territory. Two of the parties, with all their 
outfit, were transported by railroad to Rawlins Springs, and 
proceeded thence southward. The other two were sent by 
railroad from Cheyenne southward, one party to Trinidad 
and the other to Canon City. 
The primary triangulation party was placed in charge of 
A. D. Wilson, and took the field from Trinidad, the southern 
terminus of the Denver and Rio Grande Railroad, August 
18th, making the first station on Fisher's Peak. From this 
point the party marched by the valley of the Purgatoire, 
