10 TOPOGKAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [bull. 196. 
At the south the Klamath Mountains can not be distinguished 
from the Coast Range of California on the same basis, for the Eocene 
does not occur in the northern part of that State. Other formations, 
however, taken in connection with the drainage, aiford a convenient 
means of distinction, and the South Fork of Trinity River may be con- 
sidered as marking approximately their boundary. In the Klamath 
Mountains the drainage is transverse and irregular, owing in large 
measure to diversity of structure and composition, but in the adjacent 
portion of the Coast Range in California, which is made up almost 
wholly of crushed sandstones and shales, with subordinate masses 
of igneous rocks and glaucophane-schist, it is in general parallel to 
the strike of the rocks. 
There is thus developed a remarkable parallelism of the principal 
streams, not only to one another, but to the general trend of the 
coast (about N. 27° W.) from San Francisco to Cape Mendocino. 
The easternmost stream of the group is the South Fork of Trinity 
River from its head to the mouth of the Klamath. On the west 
lie the Mattole and the South Fork of Eel River, which, although 
they are within a score of miles of the coast, follow it for nearly 
60 miles before reaching the ocean. Eel River is the most impor- 
tant stream of the group, and to the east lie Mad River and Red- 
wood Creek.' Upon the headwaters of the former, Eel River has 
been encroaching and has already made important captures. The 
whole of the region bordering the Klamath Mountains on the south- 
west may be most conveniently referred to as the northern end of 
the Coasfc Range. The same peculiar drainage direction (NW.-SE.) 
may be seen in the head of Thomas and Grindstone creeks, which 
flow into the Sacramento and mark the Yallo Bally peaks as the 
southern terminus of the Klamath Mountains near the fortieth par- 
allel. The Cascade Range of Oregon and northern California is built 
up largely of igneous products along a line of great volcanoes, the 
last of which to the southward is Lassen Peak, occupying a depres- 
sion at the northeast corner of the Sacramento Valley between the 
Sierra Nevada and the Klamath Mountains, whose outlines are indi- 
cated on the accompanying map (PI. I) 1 . 
The Klamath Mountains embrace a large number of ridges and 
peaks having special names. The most important of these are the 
Siskiyou (Preston Peak, 9,000+ feet), Salmon (Thompson Peak, 9,345 
feet), Scott (Mount Eddy, 9,151 feet), Bully Choop (7,073 feet), and 
Yallo Bally (8,604 feet) along the crest of the range. They are all 
more or less conspicuous peaks rising above the general plateau of 
the group. 
1 There being some confusion in the use of names of mountains southwest of Mount Shasta, 
letters of inquiry concerning common usage were addressed to the thirty -six postmasters of the 
region, and the names Salmon, Scott, and Trinity are placed on the map in accordance with 
the majority of the replies. Concerning the Trinity Mountains the opinion was unanimous. 
