24 TOPOGRAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [bull. 196. 
decidedly mountainous, but when viewed from the crest of one of the 
high ridges the evenness of the summits becomes prominent and the 
range is seen to lack true mountain topography, except perhaps along 
the crest near the eastern edge, where the Yallo Bally, Bully Choop, 
Trinity, Scott, Salmon, and Siskiyou mountains stand out as peaks or 
clusters of peaks in the general plain. 
At the western end of the profile, by the sea, is represented the 
1,000-foot terrace, which, as we shall see later, is one of the most 
prominent and persistent along the coast. Above it the plateau front 
rises to an altitude of about 2,000 feet. The even crests of the ridge at 
this point are plainly visible from Mail Ridge near Harris, at an eleva- 
tion of 3,500 feet. In the middle view is the Sherwood peneplain, but 
the broad valley of the Garberville stage is scarcely visible. The 
upper slopes of Eel River Valley are long and gentle, while the lower 
ones are short and steep. Beyond Eel River the country is less regular 
than farther south, where, as seen from the flat summit of Bellspring 
Hill, the Sherwood peneplain has considerable development and 
passes beyond the southern end of South Fork Mountain, which is 
capped by the Klamath peneplain. South Fork Mountain is too far 
north to appear in the above profile. About South Yallo Bally the 
Klamath peneplain is preserved and after passing the crest inclines 
gently eastward for about 6 miles, descending to 6,000 feet, and then 
the slope plunges rather steeply 4,000 feet toward the Sacramento 
Valley. At an elevation of about 2,000 feet the slope again becomes 
gentle, with more or less irregularity due to erosion. Still farther 
eastward a peneplain regarded as the equivalent of the Sherwood 
plain of the west slope soon becomes gravel covered, and so remains 
for the most part until it passes beneath the terraces and alluvial 
plain of the Sacramento River.' 
ELEVATED BEACHES ALONG SEAWARD BORDER OF KLA- 
MATH PENEPLAIN. 
THE COASTAL PLAIN. 
The greater portion of the coast from Coos Bay, in Oregon, to the 
mouth of Eel River, in California, a distance of over 250 miles, is bold 
and rocky, rising in steep slopes from the shore line. The reason for 
this is found in the fact that the land is composed i>enerally of hard 
rocks. There are three exceptions to this general rule, where stretches 
along the coast are bordered by a coastal plain generally less than 100 
feet above sea level. These three tracts are, in part at least, con- 
nected with deposits of soft Neocene strata, to which is due the greater 
erosion. The first, beginning at the north, extends from Coos Bay to 
beyond Cape Blanco ; the second is about the mouth of Smith River 
and Crescent City; and the third extends from Little River, near 
Trinidad, to Eel River about Humboldt Bay. These coastal plains 
