50 
BULLETIN OF THE BUREAU OF FISHERIES. 
The San Lorenzo is a typical mountain stream. It drains a part of the moist 
western slopes of the Santa Cruz Ranges, flowing through canyons the steep sides of 
which are covered with trees and shrubs. Its water is clear and cool and is of large 
volume even during the dry season. Throughout its course the more rapid portions 
are broken by numerous quiet pools and broad, shallow areas with sandy or pebbly 
bottoms. 
The Pajaro River receives the drainage from a large interior valley, flows through 
a narrow gorge which breaks transversely across a low range of the Coast Mountains, 
and enters the narrow valley which borders Monterey Bay. Its principal tributaries 
are Uvas and Llagas Creeks from the Santa Cruz Mountains on the northwest, San Felipe 
Creek from the dry Mount Hamilton Ranges on the east, and the San Benito River, 
which drains an elongate valley extending from southeast to northwest between the 
Mount Hamilton Ranges and the Gabilan Mountains. The upper courses of the Uvas 
and Llagas and parts of the San Benito flow through rather sparsely wooded mountain 
valleys. The San Benito is an uncertain and torrential stream, subject to great floods 
in the winter. It joins the Pajaro just before the latter enters the narrow gorge in the 
mountains, and brings in such quantities of sand and gravel that the Pajaro, unable to 
clear its channel, is so thoroughly choked up that there is no apparent current for several 
miles above the obstruction. Just above its junction with the San Benito, the Pajaro 
is from 12 to 15 feet deep, the submerged and dying branches of willows along its 
banks furnishing evidence of a recent rise in the water. There are indications that a 
shallow lake once covered an extensive area in the upper Pajaro Valley, Soap Lake, a 
mere pond being all that now remains of it. The lower Pajaro is a shallow stream, 
winding here and there over the sandy floor of a broad channel with high banks, 
Salinas River flows through an elongate, narrow, and very deep valley which extends 
in the same general direction as the coast. Its course is parallel with that of the San 
Benito, from which it is separated by the Gabilan Mountains, a high and barren water- 
shed. Between the valley of the Salinas and the ocean are the well-wooded Santa Lucia 
Mountains, from which the Salinas receives its principal water supply through the 
Arroyo Seco, San Antonio, and Nacimiento Creeks. The San Antonio and Nacimiento 
drain an extensive mountain area and pass down through deep canyons nearly parallel 
with the Salinas, presenting the very unusual case of tributaries flowing in a direction 
opposite to that of the main river. In their upper courses these creeks have a consid- 
erable volume of clear, cool water, which in summer is either largely consumed in irriga- 
tion or disappears in the parched sands and gravels of the valley below. The Salinas 
itself is an erratic and torrential stream. During the dry season its feeble current shifts 
here and there over broad stretches of wind-blown sand, entirely disappearing at times 
and again rising to the surface. After the advent of the winter rains, however, it pre- 
sents a broad expanse of seething water which often threatens everything before it. 
The streams tributary to Monterey Bay, which may be more briefly referred to as 
the Pajaro system, were described as diverging from the coast, when properly speaking 
they converge toward it. The mouths of the Pajaro and Salinas are in close proximity, 
