THE LAKE BASIN. 



As may be learned from the accompanying map, Plate IV, the outline 

 of the hydrographic basin of Lake Lahontan is distinguished by great 

 irregularity, and no less unsymmetrical is the contour line within, that 

 marks tlie boundaries of the former lake. As nearly as can be estimated, 

 the total area of Lake Lahontan, as previously stated, was about 8,422 

 square miles. Its northern extremity in Quinri River Valley reached a few 

 miles north of the Nevada-Oregon boundary, and its extension southward 

 was limited by the divide at the southern end of Walker Lake Valley. 

 The distance between these points gives the extreme length of the lake as 

 250 miles. Its eastern limit was in Humboldt Valley, where the river passes 

 through the ISonoma Range, a few^ miles to the eastward of Golconda; and 

 the most westerly point near Susanville, in Honey Lake Valley, California. 

 The axis joining these two extremes is 180 miles in length. 



The area inclosed by the Lahontan beach is traversed by many 

 mountain ranges, which formed peninsulas and islands during the existence 

 of the lake, and divided its surface into a number of irregular water bodies 

 that were connected by narrow channels. The principal water surfaces 

 were grouped in two rudely parallel series, which were united at their 

 northern and southern extremities by narrow straits. The area thus 

 inclosed formed a large and extremely irregular island that bristled with 

 barren and rugged mountain ranges. For convenience in description, we 

 shall call the two main divisions of Lake Lahontan the Eastern and Western 

 water bodies. The Kastern Body covered the Carson Desert, together with 

 Buffalo, Alkali, and Churchill valleys, which open from it, extended up 

 Humboldt Valley to beyond Golconda, and occupied the southern part of 

 the Little Humboldt Valley. From the Humboldt the lake spread west- 

 ward of the Eugene Mountains and the Slumbering Hills, and entirely tilled 

 Quinn River Valley. 



The Western Body comprised the areas now known as the Black Rock 

 and Smoke Creek deserts, together with the valleys of Honey, Pyramid, and 

 Winnemucca lakes. At the north the connection between these two main 

 divisions was by a narrow strait now traversed by the lower part of Quinn 



31 



