70 'fJie Americafi Geologist y February, jsoik 
GOLD-BEARING LODES OF THE SIERRA COSTA 
MOUNTAINS IN CALIFORNIA. 
By O. H. HEiiSHEY, Bragdon, California. 
Area Discussed. 
The Sierra Costa mountains consist of a series of high, 
ragged peaks, constituting a lofty central or nucleal portion 
of the Klamath mountain system of northwestern California. 
Geologically, they are quite distinct from all surrounding 
movmtains. Beginning at Castle Crag, about 15 miles south- 
west of Mt. Shasta, they trend oiif toward the southwestward 
tor a distance of about fifty miles, ending in the extremely 
scenic granite range of the Cariboo. The width varies be- 
tween fifteen and twenty miles. They are bounded on the 
northeast by the deep and comparatively narrow depression of 
the Sacramento valley. They terminate on the southeast in an 
abrupt descent of the general surface to a lower mountain 
country and newer strata, with evidences of a profound fault 
along the boundary. On the northwest is a series of depres- 
sions (because of newer and softer strata) of which Scott's val- 
ley in Siskiyou county is an important portion. On the south- 
west the country drops ofif rather rapidly to the lower moun- 
tains of the coast section. Thus ihey come to occupy the 
northwestern corner of Shasta county, and the northeastern 
and north-central portions of Trinity county, with a narrow- 
strip along the south line of Siskiyou county. 
Topography. 
These mountains are characterized by sharp, isolated peaks 
rather than by prolonged ridges. A score or more of peaks 
attain an altitude exceeding 7,000 feet A. T. Tamarack peak 
en the northeast, reaches 7,500 feet ; Billy's peak, midway of 
the range, has 7,200 feet ; Granite peak, on the southeast (and 
immediately overlooking a country whose mountains attain 
only 3,700 to 4,000 feet) exceeds 8,000 feet ; while the bare 
granite peaks of the southwest carry their stmimits to a still 
higher level, Mt. Courtney reaching about 8,500 feet, and 
Kerr's peak of Mt. Thompson, 9,345 feet above the sea, this 
latter being the highest point of the whole so-called "Coast 
range" of California and Oregon. 
