84 LAKES OF NORTH AMERICA. 



boundary. It lies at the immediate eastern base of the Sierra Nevada, 

 from which it receives practically all of its water supply, and occupies 

 one of the minor basins composing tlie great area of interior drainage 

 known as the Great Basin. Its position on the west side of the Great 

 Basin and at the base of the great fault scarp forming the precipitous 

 eastern slope of the Sierra Nevada, is similar to the situation of Great 

 Salt Lake on the east side of the same broad desert area, and at the west 

 base of the magnificent fault scarp forming the abrupt western face of the 

 Wasatch range. Mono lake, like many other enclosed water bodies of 

 the Arid region, is of ancient lineage, as is shown by numerous beach 

 lines, carved by former water bodies, on the inner slopes of this valle3\ 

 The highest of these lines is from (370 to 680 feet above the present water 

 surface. 



The hydrographic basin of j\Iono lake has an area of nearly 7000 

 square miles, and, as in the case of the region draining to Great Salt lake, 

 is divided into two strongly contrasted portions. The southwestern part 

 is mountainous and rugged, and bristles with serrate peaks that rise over 

 six thousand feet above the lake's surface. On the mountains the snow- 

 fall is abundant, and several small glaciers exist in the liigher valleys. 

 The eastern portion of the' drainage basin is comparatively low, and is 

 arid and desert-like in character. Little rain falls on this portion of the 

 basin, and there are no* perennial streams. Only occasionally is there 

 sufficient j^recipitation to produce a surface drainage, and normally the 

 rain water and the water produced from the melting of the light winter 

 snows, is absorbed at once by the thirsty soil or returned to tlie atmosphere 

 by evaporation. 



To gain a comprehensive idea of the geography of the interesting 

 region about ]Mono lake, one should climb some commanding summit on 

 the High Sierras, on its southwestern border, and study the magnificent 

 panorama spread out at his feet. Let the reader come with me to the 

 summit of Mt. Dana, named in honor of the venerable J. D. Dp,na, one 

 of the most prominent j^eaks overlooking Mono lake, and I will endeavor 

 to point out some of the more interesting features of the land we are 

 studying. 



The summit we have reached is nearly 13,000 feet above the sea. Tlie 

 only neighboring mountains exceeding it in altitude are Mt. Lyell and 

 Mt. Ritter, which rise with dazzling whiteness against the southern sky. 

 From our station the entire Mono basin is in view, and much of its his- 

 tory can be read as from a piinted page. We are standing on one of the 



