PEALE.l DESCRIPTIVE GEOLOGY — BEAE EIVER AEEA. 587 



considerable upheaval and compression resulting in the formation of a 

 series of folds with northeast and southwest axes. Following this fold- 

 ing was a period of erosion when the beds were probably above the sea 

 level. Subsequently they formed a portion of the bottom of the early 

 Tertiary lake, to be again uplifted and eroded late in Tertiary time. The 

 Wahsatch beds show, as we have seen, a slight synclinal on the plateau, 

 and west of it, along the east- edge of the Bear Eiver Eange, south of 

 Bear Lake, they are quite sharply upturned. Following the erosion of 

 the Wahsatch, we find evidences of another lake, which was probably 

 quite local. 



BEAR LAICE VALLEY. 



, From the canon at the north end of the Bear Lake Plateau the river 

 comes out into a broad valley, which is evidently an old lake basin. It 

 is now occupied, at this point, by a marsh which, at certain seasons, be- 

 comes a lake. In this marsh Bear Eiver loses its character as a stream, 

 and emerges again at the north end of the marsh. South of the marsh 

 is Bear Lake. It occupies the depression between the Bear Lake Pla- 

 teau and the Bear Eiver Eange. It is evident that the existing lake is 

 but the remnant of one that was much larger. The view of the lake 

 from the Bear Lake Plateau is beautiful ; the water has an exquisite 

 blue tint, which is equalled by few bodies of water in any part of the 

 world. The shape of the lake is somewhat peculiar, both the north and 

 south ends being almost square-cornered. The length is 19 miles, and 

 the greatest width 8 miles. The average width of the main body is 

 about 6 miles. Toward the south it narrows to 4 miles. The shape of 

 the lake is best appreciated by reference to the map. The depth of the 

 lake, as given in the report of 1871 (p. 156), is 175 feet at the deepest 

 portion, with an estimated average depth of 40 to 60 feet. The lower 

 portion of the lake is in Utah and the upper portion in Idaho, the line 

 crossing it a little north of the mouth of Swan Creek. 



The marsh north of the lake is separated from it by a very narrow, 

 beautifully curved bar, which is only slightly raised above the level of 

 the water. This marsh is partially lake, near the main lake, and at 

 some seasons must be a real lake of considerable extent. This fact has 

 led to confusion on some maps which give two lakes. When we were 

 there, in August, the lower body was almost entirely a marsh. 



There are numerous towns in the valley. At the south end of the lake 

 Lake Town and Meadowville are two flourishing villages, with popula- 

 tions of a little over 100 each. On the west side are the following towns : 

 Swan Creek, Fish Haven, Saint Charles, Bloomington, Paris, Ovid, and 

 Liberty. Below the marsh, on Bear Eiver, the towns are Montpelier, 

 Bennington, and Georgetown. The entire population of the vallej^ is 

 about f,500. 



On the east side of the lake there is a very limited area of cultivable 

 land on which there are several small settlements. 



The soil of Bear Lake Valley is fertile and well watered, but the win- 

 ters are severe, and late and early frosts are frequent. The elevation of 

 the lake is 5,943 feet. Wheat of good quality is raised. The geology of 

 the eastern side of the lake has been given under the head of the Bear 

 Lake i)lateau. South of the lake there is a broad valley covered mth 

 Quaternary deposits, which represent an area of good agricultural land. 

 In the hills Carboniferous limestones and quartzites outcrop from beneath 

 the Wahsatch beds. The latter rise on the western flank of the Bear 

 Eiver Eange. The southwest side of the lake was not visited by me, 

 but from the notes of Mr. Mushbach it is evident that the Wahsatch 



