ABSENCE OF AN OUTLET. 35 



channels of overflow. The divide at the northern end of the Black Rock 

 Desert was the lowest point on the northern rim of the basin, but it was at 

 least 200 feet above the Lahontan beach near at hand; moreover, the rim 

 of the basin at this point was never cut by a transverse channel of erosion. 

 This point was visited by Dr. James Blake in 1872, who determined its 

 elevation to be "590 feet above the valley of Queen's [Quinn] River at 

 the place where it makes a bend to the southwest, to lose itself in the 

 Black Rock Desert."" Lake Lahontan at the point in Quinn River Valley 

 designated by Dr. Blake, was 380 feet deep, thus furnishing additional 

 evidence that the ancient lake did not attain the level of the pass in 

 question. 



During the topographic survey of the northern portion of the Lahon- 

 tan basin the highest water line of the old lake was mapped with care and 

 found continuous throughout. The lake extended into King River Valley 

 which formed a complete cul de sac, with no opening except into the Black 

 Rock Desert. At the head of Quinn River the bottom of the valley slopes 

 upward until at the divide it is several hundred feet above the horizon of 

 the Lahontan beach. The northern border of Paradise Valley was closely 

 examined by Mr. Webster, and gave positive evidence that it was not 

 a point of discharge for the old lake. During the progress of our work 

 every point on the northern rim of the basin that could be suspected of 

 having been low enough to allow the old lake to overflow was examined 

 either by the writer or his scientific assistants, and found to be unbroken 

 by a channel of discharge such as an overflowing lake must necessarily 

 excavate. 



It is important to keep in mind the absence of an outlet while reading 

 Lahontan history, as it has a direct bearing on the character of the shore 

 topography which records the extent of the lake at various stages, and 

 furnishes the key to the chemical history of the waters which formerly 

 flooded the basin. 



"Proceedings of California Academy of Sciences, Vol. IV, 1872, p. 276. 



