54 TOPOGRAPHIC DEVELOPMENT OF KLAMATH MOUNTAINS, [bull. 196. 
lignite and nodules of limonite. The bluffs are low, 10 to 60 feet, and dip 20° SW. , 
or into the ocean. 
There can be no question that these gravels are derived from the 
ancient bed of Klamath River, but near the coast they may have been 
worked over and dropped to lower terraces. So far as the writer is 
aware, fossils have not been found at Gold Bluff, either in the gravels 
or in the unconformably underlying beds containing carbonaceous 
material tilted at a high angle. Judging from their position and 
composition, it is probable that the strata underlying the stream 
gravels are of Miocene age. 
Looking a little north of west from the road near the northern 
boundary of the Hoopa Reservation, one sees Wildgrass Ridge (see 
PI. XII), which is capped bj^ the old channel of the Klamath. It 
appears to be somewhat higher than the reservation gravels, and may 
have been elevated by a fault which turned Klamath River along its 
eastern base. 
EARLIER VALLEYS OF REDWOOD CREEK AND MAD RIVER. 
Crossing the divide west of Hoopa Valley to Bairs, traces of gravel 
in the bed of the early valley of Redwood Creek were found at an 
elevation of 2,550 feet and nearly 2,000 feet above the stream. The 
early valley is marked also farther northeast, where crossed by the 
Hoopa wagon road, as illustrated in PI. XIII. 
Fog and smoke greatly interfered with general views, and especially 
with those of the Mad River country. Nevertheless, its exceptional 
character was discernible. Seen from the Hoopa road, between Korbel 
and Acorn, there are terraces in the earlier valley of Mad River at an 
elevation of 1,600 feet, although a well-developed old valley with rather 
flat bottom 3 or 4 miles in width is marked by an elevation of nearly 
a thousand feet. 
Just above the town of Blue Lake the North Fork enters Mad River 
and the broad lowland is limited by bluffs exposing tilted beds of sand 
localty rich in fossils. Ascending to the summits of these hills, one 
finds them to have flat tops which rise to an altitude of about 800 feet 
above the sea, and which form the bottom of an ancient valley of Mad 
River a number of miles wide. The soft fossiliferous beds extend up 
the old valley at least miles and afford an explanation of the devel- 
opment of a broad valley at a much lower level than the valleys of the 
streams already noted. The earlier valley of Mad River, correspond- 
ing to those here considered, is marked on the Hoopa road at an eleva- 
tion of 1,000 feet. The valley at 800 feet is of later date and connects 
with a broad terrace along the lower course of Mad River. The pres- 
ervation of these soft beds is due, in part at least, to the fact that by 
some accident Mad River was turned onto the older and harder rocks, 
in which it now occupies a canyon along the southern edge of the 
valley at the 800-foot level. 
