50 TOPOGRAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [bull.1%. 
of the earlier valleys (1) to the Klamath peneplain (2) above and the 
later valleys or canyons (3) below is shown in fig. 7. 
It should be understood, however, that the gentle features of the 
earlier valleys are not all of the same age. They have their terraces 
at various elevations, often due to local obstructions or minor oscilla- 
tions, but as a whole they may be taken as marking a long time or 
long times of relative stability, especially the Sherwood and Garberville 
stages, permitting the development of wide valleys with gentle fea- 
tures. Nearer the sea, and in some measure under its influence, the 
Sherwood peneplain was formed. At a much later stage the 1,000-foot 
terrace was developed, and it marks, approximately, the levels upon 
which the various earlier valleys terminate. 
EARLIER VALLEY OF UMPQUA RIVER. 
From Coles Valley the Umpqua flows along the eastern foot of the 
Coast Range to the sea in an extremely winding course, a feature 
which it appears to have acquired during the final stage of the devel- 
opment of the Klamath peneplain. This serpentine course was pre- 
served during the cutting of the earlier valley as well as the later. 
The earlier valley of the Umpqua is well marked only across the 
Coast Range, where it is preserved in the massive sandstone. East- 
ward, in the Roseburg region, the beds are softer and the ancient 
records have been largely destroyed. 
Near Tyee Mountain, where the river enters the comparatively hard 
locks of the range, the earlier valley is not so extensively developed 
as it is farther northwest. From the hills southeast of Elkton, where 
the river turns directly west to the sea, the plain of the earlier valley 
has a width of at least G miles and is very uniform at an elevation of 
nearly L,300 feet. Its sides are seen in the distance and are not con- 
spicuous. They are rather irregular, as if in the uplifting or subse- 
quent erosion the older Klamath peneplain had been modified. The 
best general view of the earlier valley of the Umpqua, and especially 
of its relation to the late valley, may be obtained from a summit 1 
mile west of Scottsburg at an altitude of 1,210 feet. The floor of the 
old valley is remarkably even, although cut across hard and soft 
rocks inclined at a considerable angle, and is in strong contrast with 
the later valley, which is, in general, a narrow canyon over 1,000 feet 
deep. The earlier valley is rather densely wooded, and the settlers 
along the river are confined almost exclusively to the narrow alluvial 
plains by the river in the canyon of the later valley. 
EARLIER VALLEYS OF COOS AND COQUILLE RIVERS. 
The soft rocks in the Coos Bay region have not preserved the 
ancient landmarks near the coast, but 15 or 20 miles back from the 
coast earlier valleys, both of the Coos and of the Coquille, may be 
found at an elevation of 1,500 feet. Farther east these old valleys 
