232 DOUGLAS WILSON JOHNSON 
(Fig. 2). From a distant view one gets the impression, however, 
that the elevated valley floor slopes eastward, or away from the 
fault scarp instead of toward it. I interpreted this to mean that 
a stream formerly flowed from west to east through the block, 
probably to unite with Williamson River, and that it maintained 
its antecedent course until half the present altitude of the rising 
block had been attained; then an excessive uplift dammed the 
stream and turned it southward along the Klamath graben, while 
the deserted valley was later raised to its present altitude by con- 
tinued uplift of the range. Regarding this remarkable valley 
Dr. Gilbert writes: “The hanging valley you noted seems to be 
the only one of its type. I was able to verify your interpretation.” 
Fic. 2.—Deserted antecedent gorge in uplifted lava block south of Fort Klamath 
settlement. 
In this connection I may perhaps refer to another possible 
example of the same physiographic type, recorded more than ten 
years ago, but not described in print because of the hasty char- 
acter of the observations on which my tentative interpretation was 
based. In the summer of 1906 I passed through the Parowan 
Valley at the western base of the high plateaus of Utah. This 
depression (Fig. 3) is well shown on the Kanab topographic quad- 
rangle, and was interpreted as a graben similar to the one described 
above. The great fault which bounds the valley on the southeast 
is abundantly attested by both physiographic and stratigraphic 
evidence, as I proved by several traverses across the fault southeast 
of Summit, Parowan, Paragoonah, and elsewhere. On the north- 
west the valley floor terminates abruptly at the base of a pronounced 
scarp, which is more or less dissected, but which shows occasional 
well-marked triangular facets such as characterize the fault faces 
