PHYSIOGRAPHY OF KLAMATH MOUNTAINS 145 
except in their broader outlines. They embrace both sedimen- 
tary and igneous rocks, ranging in age from the Paleozoic to 
the Tertiary, though the later rocks form only a small portion 
of their mass and occur only in the larger valleys of the region. 
This group of mountains, which is clearly separated from the 
Sierra Nevada by the broad structural valley of the Sacramento, 
has been distinguished from the Coast Ranges to the north and 
south mainly upon geological hypotheses, it having been sup- 
posed that the ranges on either hand were of more recent origin, 
involving essentially younger strata. It yet remains to be shown, 
however, whether a satisfactory boundary can be so established, 
particularly upon the south. The metamorphic rocks of the 
Klamath system, including its schists and limestones, appear to 
be represented along the coast at intervals even as far south as 
San Francisco or even farther. The slates, cherts, and lime- 
stones of the Franciscan series, moreover, have their representa- 
tives among the Klamath Mountains and throughout the Coast 
Ranges. 
GENERAL FEATURES. 
The chief ranges—The mountains included in the Klamath 
group have generally been regarded and described as a physio- 
graphic compler—a group of mountains without any definite 
order or relation, occupying a position at the junction of all 
the other systems in this portion of the coast. It is the pur- 
pose of this paper to call attention to a few of the more promi- 
nent facts pertaining to this question and to point out if possible 
some general system in their arrangement that has heretofore 
escaped notice. While it cannot be denied that the group 
holds in the main the position above described, it is believed 
that their disorder has been largely imagined. On the whole the 
group embraces a number of more or less independent ranges, 
some of which are much more prominent than others, some of 
them not having yet been distinguished by recognized names. 
They may be readily classed into two main systems which are 
believed to have a definite relation to the dynamical history of 
