26 TOPOGKAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [bull. 196. 
NORTH OF ROGUE RIVER IN OREGON. 
The seaward edge of the Klamath peneplain is a very irregular line 
both in elevation and in its approach to the coast, and of equal or 
even greater irregularity are the ancient sea beaches on the slope 
from the edge of the peneplain to the coast. 
A section of the marine terraces on the plateau front was made 
about 12 miles north of Port Orford, in the vicinity of Denmark, 
along the trail to White Mountain. It is illustrated in fig. 3. The 
coastal plain rises from a low border on the coast at Floras Lake to 
98 feet at Denmark. It is part of the large plain, ranging in width 
from 1 to over 4 miles, generally having an altitude of less than 200 
feet, and extending from near Coos Bay to Port Orford. Its surface is 
even and often swampy, and slightly rolling with sand hills. In Cape | 
Blanco the plain rises at a sea cliff to 225 feet. Near the northern 
and southern ends the sea cliff of this coastal plain is over 100 feet 
in height, but from Bandon to Floras Creek it is lower, and is bor- 
bered here and there by barrier lakes or ponded streams. Continu- 
ing the section from Denmark, at 500 feet is a distinct terrace of 
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Fig. 3.— Profile of marine terraces 12 miles north of Port Orford, Oreg. 
small extent, but at 1,000 feet is a much larger one, having a width 
of over a mile. This level is well marked on the next spur to the 
northward, 2 miles west of Hare, on the road from Langlois to Myrtle 
Point, and is cut on various hard rocks, such as serpentine, schists, | 
and igneous rocks, as well as relatively soft sandstones. Some well- 
rounded pebbles are found at this place, marking the ancient sea 
beach. Marshy spots like those on the coastal plain also occur at this 
level. 
Rising over a steeper slope to nearly 1,500 feet, one arrives at a third 
terrace, several miles in width. Like the 1,000-foot terrace, it has 
suffered much from erosion, yet its character is unmistakable. East- 
ward it is limited by a sea cliff. There is an abrupt change from the 
flat terrace to a steep slope, and then a more gradual change to the 
gentle slope of White Mountain summit, where the peneplain is 
traceable at an altitude of about 2,200 feet. 
The sea beach at an elevation of 1, 500 feet is the highest seen along the 
coast of the Klamath Mountains, and is very distinct at a number of 
points; for example, by the summit of Bills Peak in the south part of 
