228 GEOLOGICAL SUEVEY OF THE TEREITOEIES. 



Although a basin in fact so far as its water-drainage is concerned, 

 yet its surface does not sweep down from the surrounding rim to a cen- 

 tral depression, but, on the contrary, its areas of greatest depression are 

 to be found near the borders, especially along the eastern and western 

 sides, while its central portion reaches a much greater elevation, and is 

 broken into a series of detached ridges. This will be seen by an exami- 

 nation of the elevations along the line of the Central Pacific Eailroad. 

 For example, at Brigham Station, on the border of Salt Lake, it is 4,220 

 feet above the level of the sea, while at Pequop, the next station west 

 of Toana, it reaches 6,184 feet; from this it again gradually descends to 

 Desert, the second station east of Wadsworth, where it is only 4,017 

 feet, or about 200 feet below the level of Salt Lake. The highest ranges 

 in it will probably exceed the greatest elevation here given as much as 

 1,500 or 2,000 feet. The elevations at the points of greatest depression 

 in the southeastern and southwestern portions have not been accurately 

 determined, but it is known that in the vicinity of Sevier Lake it is not 

 more than 4,500 feet above the level of the sea. A comparison of these 

 elevations with those of the broad mountain belt lying east from the 

 Wahsatch Kange to the Black Hills of Wyoming will bring out this 

 feature more clearly and forcibly, and at the same time afford us a means 

 of comparing the climate of the two sections, so far as influenced by 

 elevation, in the same latitude. The highest point of the Union Pacific 

 Eailroad on the western side of this belt is at Wahsatch Station, 6,879 

 feet above the sea-level. The highest on the eastern side is at Sherman, 

 8,242 feet. The lowest point between the two is at Green Eiver, where 

 the elevation is 6,140 feet, or about 2,000 feet above the lowest level of 

 the basin. Some of the intermediate ranges, as the Uintah Mountains, 

 reach a height of 10,000 or 12,000 feet, and the peaks occasionally 

 exceed 13,000 feet. That this difference in altitude must produce a 

 considerable difference in the climate is evident. North the difference 

 is not so great. 



This depression below the general level is a fact of much importance 

 in estimating the agricultural resources of this extensive interalpine 

 region, as it indicates a very material moderation of climate. And that 

 which might be inferred theoretically has been shown by extensive ex- 

 periments to be true in fact, as can be seen from the list of the produc- 

 tions of Salt Lake Valley given in my last report. 



MOUNTAINS. 



The mountain features of this basin are somewhat peculiar, differing 

 in some important respects from those of the sections lying east and 

 north, and exerting a decided influence upon the channels of travel and 

 internal commerce, and upon the lines of settlement and centers of 

 population. The Wahsatch Eange, which runs almost directly north 

 and south near the one hundred and twelfth meridian, forms the eastern 

 rim, and presents an immense terrace wall, bracing up the broad ele- 

 vated table-land which stretches out eastward of it, and of which it may 

 be said, with more than mere figure of speech, to form the western es- 

 carpment. It follows that its western slope presents a greater descent 

 to reach the level of the lake than its eastern to reach the level of Green 

 Eiver. Excerpt where cleft by the Ogden, Weber, and Provo Elvers, it 

 presents a continuous ridge rising abruptly from the narrow plains, 

 seldom sending out on this side foot-hills or slopes, but plunging ab- 

 ruptly down beneath the debris that presses against its surface. This 



