14 SURVEY OF FISHING GROUNDS, 1915. 
weather is barren of possible fishing grounds; only two spots were 
located. The continental shelf, 30 miles wide off Tillamook Head 
on the north narrows to 12 miles off Cape Kiwanda in the south and 
is covered throughout with green mud. 
West of Tillamook Rock, 25 to 30 miles, was discovered an area 
of gravel, coarse sand, blue mud, and granular shale. A small patch 
of gravel bottom was located 22 miles west of the mouth of Nehalem 
River. Near Cascade Head there is a patch of fine gravel in 42 
fathoms, near which, in 1914, a good scallop catch was made. 
Newport section.—The Tillamook section marked the southern limit 
of the 1915 investigation, but for completeness a brief description of 
the Newport, Heceta Bank, and Coos Bay sections is taken from 
the report on the 1914 survey: 
Between Yaquina and Alsea Bays and about 12 miles offshore, a ridge was discov- 
ered on which 30 fathoms was the minimum sounding made by the Albatross, although 
Capt. Carrol, until recently of the Decorah, reports that he made one sounding of 20 
fathoms in this vicinity. This ridge is the outer wall of a submarine valley having, 
so far as sounded, an extreme depth of 47 fathoms, shoaling at its mouth to 42 fathoms 
and merging with the flat of the continental shelf at the 50-fathom curve. On both 
sides of the ridge, and principally at the upper end of the submarine valley formed 
by it, the late summer run of halibut, developed by this survey, was found. The 
bottom across the head of the valley and through the greater extent of its floor is of 
coarse gray sand, carrying a very rich growth of such organisms (sea anemones and 
pennatulids) as are typically found on good halibut bottom. 
Over the ridge and principally on its northwestern and southern slopes is found 
what has been designated as broken bottom—composed of materials of a mixed char- 
acter, shale, gravel, sand, and mud—in patches varying in size and composition, 
but all very rich in bottom-living organisms. On the western slope is a patch of 
coarse gray sand and another of gravel, apparently of considerable extent, though 
no great number of soundings were made there. On this patch a good lot of fish 
were taken. 
Heceta Bank section.—Similar to the ridge off Newport, but larger and in somewhat 
deeper water, there is a large, roughly triangular plateau called Heceta Bank, between 
25 and 30 miles offshore to the southwestward of Heceta Head. It is composed largely 
of shale too hard for good halibut bottom, while the submarine valley formed by it 
is too soft, having a bottom of soft green mud. Several patches each of broken bot- 
tom and black sand occur both on the flat of the bank and on the offshore slopes. 
The most promising broken bottom is in the vicinity of set x1, where a lot of fish 
were taken in the spring of the year (set 1). Black sand is considered good black 
cod bottom and on one patch of it (set x) a fair catch was made. 
Between Heceta Bank, Alsea Bay, and Heceta Head is a large area of fine gray 
sand which below Heceta Head is encroached upon by the green mud of the sub- 
marine valley formed by Heceta Bank. Off the mouth of the Siuslaw River is a 
small isolated patch of gravel surrounded by fine gray sand. The mud line trends 
in from the 70-fathom line toward the Umpqua River, where it reaches the 30-fathom 
curve less than 2} miles offshore. Another gravel patch about 7 miles below the Ump- 
qua River lies within this mud area but 6 miles from shore, and south of this the mud 
recedes until it lies beyond the 70-80-fathom line 10 miles off Coos Bay. 
Coos Bay section.—In a line between the Umpqua River and Coos Bay, three sets 
(XXVU, xxix, and xxx) were made on fine gray sand, which occurs everywhere 
in this region inshore of the mud. As developed by the above sets, this sand bottom 
