234 DOUGLAS WILSON JOHNSON 
correct interpretation the case is of interest as representing an 
earlier stage of the history recorded in the Fort Klamath example; 
for in the Parowan case the deserted valley has not yet been raised 
much above its former level, and the lake initiated by the rising 
obstruction has found no new outlet. It is possible that heavy 
rains might so raise the lake-level as to cause it to spill out through 
Fic. 4.—Fault-block ‘‘splinter”’ on face of young block mountain. Modoc Point 
looking north from Plum Ridge. (Photo by A. K. Lobeck.) 
the gorge itself before another outlet was found. Unfortunately 
I was not able to visit the entrance to the gorge, nor otherwise 
to test the validity of my tentative interpretation. Observations 
based on a reconnaissance map with contour interval of 250 feet, 
supplemented by visual inspection from a distance of four or five 
miles, must not be accorded too high a value. 
Returning to the Klamath graben we may note that from 
Cihloquin southward a very young fault scarp forms the imposing 
