94 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



Five or six miles inside this shore-line and parallel there- 

 with the Mattole River runs to the northward and empties 

 into the ocean two miles north of Punta Gorda; and 20 to 

 25 miles further inland and parallel with the shore flows 

 the Eel River from the southeastward, through a deep 

 valley that opens on the coast in latitude 40^ 40' just south 

 of Humboldt Bay. The outer of these two parallel ranges 

 rises to an elevation of 4,265 feet in latitude 40° 09', only 

 2^ miles from the shore. Under the highest parts of this 

 ocean barrier, within a distance of 20 miles along the 

 shore, head four deep submerged valleys, between latitude 

 40° 06^' and latitude 40^ 23'. 



The details of this part of the coast are as follows: — 



18. The King Peak Submerged Valley. 



A submarine ridge named the Tolo Bank runs southward 

 from Point Delgada at Shelter Cove, in latitude 40° 01% for 

 ten miles or more. It has as little as seven fathoms of 

 water upon it, and the tail of the 15-fathom curve lies five 

 miles off shore. The depth of the marginal plateau at 100 

 fathoms is eight miles from shore. Just north of this bank, off 

 Shelter Cove, there has been developed a deep, submerged 

 valley, where it breaks through the marginal plateau and 

 runs sharply into the immediate coast-line under the culmi- 

 nating point of the crest -line of the coast mountains. The 

 head of this submerged valley is 100 fathoms deep at half a 

 mile from the shore, and the depth of 25 fathoms almost 

 reaches the rocks under the cliffs. The loo-fathom line of 

 the plateau lies six miles off Point Delgada, and where this 

 valley breaks through it the depth reaches more than 430 

 fathoms. The slopes of the sides of this valley are quite 

 steep; in places the bottom drops 100 fathoms in a quarter 

 of a mile. The general direction of the valley, which is 

 nearly straight and parallel with the Tolo Bank, is S. SW., 

 and its length to 450 fathoms is seven and a half miles. 

 The bottom of the plateau is fine gray sand out to 45 

 fathoms, and in two or more points on the north plateau 



