CHAPTER V. 



DESCRIPTIVE GEOLOGY— BEAR RIVER DRAINAGE AEEA. 



Bear River— Upper Bear River Valley — Smith's Fork— Sublette Range — 

 Thomas' Fork — Bear Lake Plateau — Bear Lake Valley — Preuss Range — 

 Soda Springs and Bear River Bend — Soda Springs Valley — Soda Springs 

 Hills — Basalt Valley — Bear River Range — Gentile Valley — Middle Canon 

 of Bear River — Cache Valley — Malade Range — Malade Valley — Blue 

 Spring Hills. 



The present chapter will he devoted to the description of the south- 

 western portion of the district, in which the drainage is tributary to 

 Bear River. It is therefore a portion of the Great Basin. Bear River is 

 the great artery of this whole region. In considering it I shall follow the 

 plan of the preceding chapter, and shall take up the successive streams, 

 alternating with such mountain ranges as intervene. The entire area 

 drained by the Bear and its branches within our district is nearly 5,000 

 square miles, or over one-third of the entire district surveyed by us 

 during the season. 



BEAR, RIVER. 



Bear River enters our district in about longitude 111°, flowing slug- 

 gishly with large curves through a broad valley which continues north- 

 ward to the mouth of Smith's Fork, a distance of about 25 miles on a 

 north and south line. From this, which we call the Upper Valley, it 

 turns slightly to the northwest into a narrower valley which reaches to 

 the mouth of Thomas' Fork. Receiving the latter stream in a broad valley 

 opposite the Sublette Range the river turns abruptly to the southwest, 

 and enters the canon-like valley at the north end of the Bear Lake 

 Plateau, through which it cuts to the valley of Bear Lake. In this 

 canon it turns abruptly to the north, making a right-angled bend. The 

 valley in the canon is generally broad and meadow-like with good grass. 

 Several ranches have been located below the bend and seem to be flour- 

 ishing. Soon after the river comes out into Bear Lake Valley it loses 

 itself in the marsh that extends northward from Bear Lake. Below the 

 marsh the river flows through a wide marshy flat, covered with a growth 

 of coarse grass. The soil in this region is rich and the valley has been 

 well settled. Numerous towns are found along the river. The course 

 of the river here is approximately northwest until within about 6 

 miles of Soda Springs, where there is a sharp turn to the westward 

 along the south edge of a basaltic flow. After keeping this direc- 

 tion for about 5 miles a northern course is assumed and the river 

 curves to westward and southwestward in the valley opposite the mouth 

 of Soda Springs Creek. Four miles west of the mouth of the latter the 

 Bear cuts across the northern end of the Bear River Range at the south 

 side of a gap that is about half a mile in width. Here it is in low canon, 

 a basaltic wall bounding it on the north and the limestones of the range 

 outcropping on the south bank. For three or four miles beyond the gap 

 the river keeps close to the foot of the range. The cause of this may, 

 perhaps, be seen in the basaltic flow which came from the craters still 



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