78 LAKES OF ]S'OKTH AMERICA. 



The elevation of the lake's surface varies somewhat during different 

 years and from season to season, owing to climatic changes, and to the 

 fact that the flow of the streams supplying it is interfered with for pur- 

 poses of irrigation. Surveys made May 1(3, 1883, gave a surface level of 

 4218 feet above the sea. 



Its area is also changeable. On a map made from surveys under the 

 direction of Lieut. Stansbury, in 1850, it is represented as having an area 

 of about 1750 square miles. A second map, made in connection with the 

 Fortieth Parallel survey, in charge of Clarence King, in 18G9, shows an 

 area of 2170 square miles ; the increase in 19 years being 420 square 

 miles, or 24 per cent. Its outlines when these surveys were made are 

 shown in Plate 15. 



At its highest observed stage in 1869, it had a maximum depth of 49 

 feet, and an average depth of approximately 19 feet. In 1850, the maxi- 

 mum depth was 36 feet, and the average about 13 feet. Since 1875, 

 careful records of the fluctuations of level have been made and both 

 annual and secular changes noted. i The annual high-water stage occurs 

 in June, and is due to the melting of the snow on the Wasatch and 

 Uintah mountains. The fluctuations embracing a series of years have 

 not been found to be regular in their periods and are not coincident with 

 observed climatic changes. 



The shores of Great Salt lake are low except Avhere a mountain uplift 

 projects into it from the north, forming a rocky promontory, and for a 

 short distance on its south shore where it touches the northern end of the 

 Oquirrh mountains. Its surface is broken by several islands, of which 

 two are short mountain ranges of the type so characteristic of the Great 

 Basin. These rise more than a thousand feet above its surface and are 

 rugged and precipitous. They stand like Nilometers in the saline waters, 

 and on their sides are many horizontal lines marking former levels of the 

 lake's surface. The highest of these scorings is about 1000 feet above 

 the present water surface. 



The scenery aljout this great lake of the INIormon land and in the encir- 

 cling mountains is unusually fine, in spite of the aridity and the generally 

 scant vegetation of the region. The sensation of great breadth that the 

 lake inspires, together with the picturesque islands diversifying its sur- 

 face, and the utter desolation of its shores, give it a hold on tlie fancy, and 

 wakens one's sense of the artistically beautiful in a way that is unrivaled 



1 The records of these changes up to 1890, together with a discussion of their signiticance, 

 is giveu by G. K. (iilbert, in Monograph No. 1, U. S. Geological Survey. 



