PBO(JUOP llANGE. 505 



logical resemblances, and in part to its relation to the other bodies of lime- 

 stone in the adjacent regions. No organic remains that were capable of 

 specific determination were collected; highly- altered specimens of Productus, 

 associated with crinoidal stems, occur here, but of no special importance. 



Mount Pisgah is a sharp, narrow, somewhat isolated limestone ridge 

 south of Dondon Pass, whose beds resemble in lithological character those 

 of Lookout Peak; their structure being that of an anticlinal fold, with a 

 north and south axis, whose eastern member has been partly eroded. On 

 the western foot-hills is a development of finely-laminated slates consti- 

 tuting part of the western fold, the entire structure being apparently in 

 conformity with that of Lookout Peak. Our examinations at this point 

 were extremely brief, and no fossils were found. By reference to the lower 

 section, upon the geological sheet, the position of Mount Pisgah and its 

 anticlinal structure will be readily seen. 



Peoquop Eange. — This range lies upon the west side of the Gosi-Ute 

 Valley, and in many of its physical and geological features is almost a 

 counterpart of the Gosi-Ute Range. As it rises, however, between two 

 broad desert valleys of nearly equal elevation, it presents from the eastern 

 side a much less bold and prominent appearance than does the Gosi-Ute 

 Eange. Its trend is almost due north and south, with a length of 52 miles, 

 and is for the greater part of this distance even narrower than the range on 

 the opposite side of the valley. It attains its culminating point in Spruce 

 Mountain, which reaches an altitude of 10,400 feet above sea-level. Other 

 prominent peaks are Grand Peak, 8,300 feet, at the southern end of the 

 range, and at the northern extremity Orford Peak, 7,556 feet. 



This range is one of extreme dryness, only one creek of any consider- 

 able length being known, and but few small obscure springs. As the strata 

 along the northern end of the range for the most part dip easterly, there are 

 along its eastern base numerous springs and ponds coming to the surface 

 on the desert, just beyond where the strata pass under the valley-deposits. 

 Along the great freight-road which runs from Toano southward, near the 

 Peoquop foot-hills, a number of wells have been sunk in the desert Qua- 

 ternary, yielding, after passing through sandstones, sandy shales, and clays, 

 good water at a depth of 80 to 100 feet. 



