THE CHICAGO ACADEMY OF SCIENCES. 



19,000 square miles. The waters of this lake fluctuated in depth, finally 

 becoming so high that an outlet was effected to the north into the Snake 

 River. The western lake, Lake Lahontan, did not attain the size of 



FlG. 5. 



The Great Basin of Utah, showing Quaternary Lakes. Bull. U. S. Geol. 

 Surv., No. 11, pi. 1. 



Lake Bonneville (reaching an area only of 9000 square miles) and 

 was without an outlet. Numerous smaller lakes also developed, most 

 of which have long since disappeared. Great Salt Lake and Servier 



