GEOLOGY OF THE SOUTHERN COAST RANGES 553 
Santa Lucia and San Jose ranges. South of the Santa Lucia, 
between it and the San Luis range, are the broad and fertile 
San Luis and Los Osos valleys opening northwestward to Morro 
Bay. A series of sharp peaks extends from a point a little south 
of the town of San Luis Obispo northwest to Morro Rock 
separating these valleys from the foothills of the Santa Lucia 
range. 
The Santa Lucia range as far as its recent movements are 
concerned forms a geological unit, and viewed from the south 
it presents a bold and comparatively regular front and even sky 
line. The highest portion has an elevation of nearly 3000 feet, 
and the summit a width of two to four miles. The topography 
of this range while presenting certain common features yet varies 
greatly in different portions, owing to the marked variation in 
resistency offered to erosion by the different geological forma- 
tions. The Monteveys hales, which are mostly confined to that 
portion east of Cuesta Pass, are cut by deep V-shaped canyons 
while northwest of this pass the soft Knoxville shales, extend- 
ing longitudinally through the centre of the range, exhibit a suc- 
cession of open valleys. 
The granite mountains (San Jose range) in the northeastern 
corner of the area surveyed reach an elevation of nearly 2000 
feet, but do not seem so high because of the elevated valleys 
about them. They are cut by narrow canyons, but do not rise as 
abruptly from the adjoining valleys as the Santa Lucia range. 
This elevation of land isa magnificent example of an ancient 
base leveled mountain range. Viewed from most any point 
along the foothills of the Santa Lucia range the numerous fur- 
rowed ridges fail into an even sky line many miles long. 
The San Luis range attains an elevation of a little over 1800 
feet. It consists of a series of sharp ridges traversed by deep 
narrow canyons. To the east it lessens in height and finally 
blends with the Santa Lucia range. 
The line of buttes extending from the vicinity of San Luis 
Obispo northwestward and terminating in Morro Rock constitutes 
the most remarkable scenic feature in the landscape. The buttes 
