Geological Survey of California. 259 
These traces of extinct glacier action were afterward discovered by us 
Shasta. 
the Henness pass. Thus our observations, when combined, will enable 
US to give the first approach to a tolerably accurate map of this great 
chain of mountains, It is uncertain, as yet, how and in what form our 
topographical work will be laid before the public, except that the publi- 
cation of the maps of the vicinity of the Bay of San Franci do 
the Monte Diablo region has been determined on, and they will be 
Soon placed in the engravers’ hands. It is believed, however, that suc 
arrangements will be made as shall ensure the publication of a map of 
the entire State, greatly improved on anything which has yet appeared, 
and as large as can be conveniently used for a wall-map—say, on a scale 
of twelve miles to the inch. A map of the central portion of the State, 
own very numerous hypsometrical observations. The data collected in 
the course of these oe ccenies ave been employed by, Major Wil- 
liamson in working up the observations taken by the U.S. and California 
in 1861, in 
below the level of the ocean. 
eology.— t time, and including this season of 
vo. e p r 
field-work, we may be said to have been chiefly engaged in making a 
ological reconnoissance of the 
tate, and we have travelled 
But conside 
