100 United States Survey of the Territories. [February, 
beds resting directly upon metamorphics, we now find a full series of 
the sedimentary formations, beginning with the Silurian. Numer- 
ous interesting stratigraphical phenomena were observed and 
studied with a view to determine their relations to the main 
mountain-chain. An ample amount of evidence has been obtained, 
more particularly by this means, to speak positively respecting 
the geological age of the Wind River mountains. These latter, in 
this region, form the main Rocky Mountain chain, and the deter- 
mination of their age will necessarily throw much light upon the 
same question arising in other portions of the same range. It 
will be possible to speak with a certain degree of precision of 
either the local, varying (as to time) elevation of the mountains 
or to refer it to one particular epoch for the distance of many 
hundreds of miles. 
Camp Brown is located in the valley of the Little Wind river, 
which there is of considerable breadth. The famous hot springs 
there were examined. As the main peaks of the Wind River 
mountains were mostly inaccessible from the east side, it was 
deemed advisable to make the ascents of the highest from the 
west. Therefore the party traveled along the eastern foot-hills, 
through a very rugged country, until Stambaugh was reached. 
July 22d the party again left Stambaugh and marched along — 
the headwaters first of Sweetwater river and then of the eastern 
tributaries of Green river. Several of the highest peaks were 
ascended, and the greatest altitude reached found to be about 
13,700 feet. This latter was on what the settlers generally des- 
ignate as Frémont’s Peak. From careful comparison of Fre i 
mont’s report with the observations made by the party, it is 
evident that a misapplication of the name has been made, and 
that the peak in question is not the one ascended by that intrepid 
explorer of an “early day.” 
Having reached the northern limit of the district, the route 
was reversed and the western foot-hills of the main ranges exam- 
ined. Here, as well as in the mountains proper, were noticed the 
remains of enormous ancient glaciers. Moraines, covering many 
square miles, often a thousand feet in thickness, extend down- 
ward through narrow valleys, now containing rushing streams. 
Striation, grooving and mirror-like polish of rock in situ denote 
the course taken by the moving ice-fields that have left thes¢ 
marks of their former existence. From all appearance the cessa- 
