98 CALfFORXIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



termination of the Coast Range of mountains coming from 

 the south-east and forming the great ocean barrier. This 

 range is, however, divided lengthwise by two valleys, each 

 carrying a stream that rises in the southeast. These streams 

 run nearly parallel with the coast-line. The western stream 

 is the Mattole River and the eastern is the Eel River, with 

 two principal forks. The former rises in latitude 39° 55', 

 and averages six miles only from the coast, and the latter 

 rises in latitude 39° 17', longitude 123° 20', and averages 25 

 miles from the coast. 



We have stated that the Mattole empties near the 

 head of the Mattole submerged valley; the Eel River 

 empties through a broad, beautiful, low-lying valley, 13 

 miles northward of Cape Mendocino, but there is no indica- 

 tion of a submerged valley at its debouchment. 



The high terminal of this part of the Coast Ranges em- 

 braces Punta Gorda, Cape Mendocino, and False Cape, or 

 Cape Fortunas. Signs of their extension are shown by the 

 soundings to the northwestward, where submarine peaks 

 rise above the general plateau of the Pacific ; and it is a 

 curious fact that all the recorded submarine earthquakes 

 along the Pacific Coast of the United States have been felt 

 off Cape Mendocino. 



Within 50 miles northward of Eel River empty the Mad 

 and Klamath Rivers. The great southern fork of this river 

 is the Trinity, running parallel with the general trend of the 

 coast south of Mendocino ; but there are not the slightest 

 indications of submerged valleys off their mouths. 



Practical Bea7'ing of these Northern Submerged Valleys. — 

 Two problems are at once suggested by these four sub- 

 marine valleys; one is eminently practical: Steam-coasting 

 vessels bound for Humboldt Bay, when they get as far 

 northward as Shelter Cove, haul into the shore to find 

 soundings and then continue their course parallel to the 

 shore. One vessel has been lost by failing to find bottom 

 until close upon the rocky coast, and blame was attached to 

 the captain. This steamer doubtless sounded up the axis of 



