10 Geological Survey of California. 
Art. Il.—Notice of the Explorations of the Geological Survey of 
California, in the Sierra Nevada, during the summer of 1864. 
In the September number of this Journal (vol. XXViil, page ] 
298) a notice was inserted giving a sketch of the explorations of © 
Since the last number of the Journal was issued, some further : 
particulars have been received with regard to the peak ascended a 
on the 6th of July, to which the name of Mt. Tyndall was given, — 
and also a brief account of the attempt made to get on to the — 
highest points. 4 
The ascent of Mt. Tyndall was a very difficult and dangerous — 
one; but the summit was reached without accident either to Mr. q 
King or his companion, although the trip required that sev | 
eral nights should be spent at an elevation of over 12,000 feet, — 
of course without fire, and with but scanty covering. From ~ 
the summit of Mt. Tyndall, which is considerably over 14,000 — 
feet high, there appeared two other peaks of equal elevation and — 
two still higher, all within a distance of seven miles of this. Mr. _ 
King says, “of the two highest, one rose close by, being hardly ; 
a mile away; it is an inaccessible bunch of needles. ‘I'he other — 
was equally inaccessible from any point on the north or west — 
side. ‘The first-mentioned was about 150 feet above us, the other — 
was six or seven miles distant and I should think fully 850 feeb — 
higher than the peak we were on. Within our field of view 
were five mountains over 14,000 feet and about fifty over 18,000. — 
The five highest peaks are all in the eastern ridge. Owen’s val- 
ley, a brown sage plain, lies 10,000 feet below on the one side, — 
and Kern cafion, once the rocky bed of a grand old glacier, — 
4000 feet down on the other. About fifteen miles north of here, — 
King’s river cuts through the western ridge and turns at a right 
angle toward the plain. North of this point, again, the two 
great ridges unite in a grand pile of granite mountains, whose 
outlines are all of the most rugged and fantastic character. — 
Twenty-five miles south, the high group ends, there (certainly 
for a breadth of sixty miles) forming one broad, rolling, forest-_ 
covered plateau, 8000 to 9000 feet in elevation.” ; 
“From Mt. Brewer to Kaweah Peak, the two culminating - 
points of the western ridge, for a distance of fifteen miles, there is 
nothing that can be called a separate mountain: it is, rather, a 
— mural ridge, capped by small sharp cones and low ragged 
es, all covered with little minarets. At one place the ridge 
