GEOLOGICAL SURVEY OF THE TERRITORIES. 



CHAPTER I. 



FEOM OGDEN, UTAH, TO FOET HALL, IDAHO. 



In my previous reports I have endeavored to present such facts in re- 

 gard to the geology of the country lying between Omaha and Salt Lake 

 as my time and opportunities have enabled me to secure. In a subse- 

 quent chapter I shall pass this region again under review, adding such 

 new matter as the investigations of the -pRst seasons have brought to 

 light. 



In order that the results of the explorations of 1871 might be con- 

 nected with those of preceding years, it was thought best to make Ogden 

 the point of departure. The latitude and longitude of Salt Lake City 

 are probably as well fixed as those of any point west of the Mississippi. 

 The elevations taken along the line of the Pacific Eailroad were as- 

 sumed to be correct, and the geography as well as the geology of Salt 

 Lake Valley were known in general terms. Our camp was located on a 

 middle terrace one mile east of Ogden Junction, at an elevation above 

 tide-water of 4,517 feet. Extending along the eastern side of the valley, 

 with a trend nearly north and south, is a lofty and picturesque range of 

 mountains — the northern section of the Wahsatch Range. Far south- 

 ward, beyond the southern end of the Great Salt Lake, these mountains 

 seem to extend, apparently growing more lofty and more picturesque, a 

 gigantic wall inclosing one of the most beautiful valleys in the West. 

 From the terraces, which form a conspicuous feature along the base of 

 these mountains, one can obtain a full view of the wonderful body of 

 water which has given name and character to this region. I will not 

 attempt here to describe the scenic beauty of this region 5 it has already 

 been done many times 5 it must be seen by the traveler to be understood, 

 and once impressed upon the mind it becomes a perpetual pleasure 

 thereafter. 



The discussion of the Post Pliocene deposits and other prominent geo- 

 logical features of this valley is reserved for a subsequent portion of 

 this report. It is my purpose at this time simply to note the impres- 

 sions obtained of the geological structure of the country from point to 

 point in the journey northward from Ogden to the valley of the Yellow- 

 stone. 



The range of mountains which form so conspicuous and attractive a 

 feature along the eastern shore of the lake, and north from Ogden, is 

 composed mostly of quartzites and limestones, which present excellent 

 examples of stratification. Just in the rear of our camp there is an 

 illustration in which a thousand feet or more of layers of quartzite, vary- 

 ing from a few inches to several feet in thickness, are bent in the form of 

 an arch (Pig. 1) as if the force had been applied from beneath, near the 

 central portions, but that the sides or ends had lopped down for want of 

 support. There are many examples of these peculiar features in this 

 range, produced by local influences, but connected with the general 



