st. joux.]) MOUTH OF HOBACK’S RIVER—PLACER DEPOSITS, &c. 201. 
naceous layers, with partings of dark, almost fissile, shale charged with 
charcoal particles. These deposits, in which the argillaceous element pre- 
dominates, incline at an angle of 17° about W. 18° St They belong to the 
series 1 of the foregoing section. Inthe high bluffs on the south side of the 
Hoback, just above the last noticed locality, heavy ledges of rather coarse- 
erained, thin-bedded, bluish-gray sandstone outcrop ‘at an elevation 175 
to 200 feet above the stream, “the dip being to the southwest at an angle 
of 20°. The beds afford only obscure vegetable remains, like tree- trunks. 
They enter largely into the rock materials composing the outlying hills 
on the east flank of the John Day ridge. The gray sandstones and 
argillaceous beds outcrop in the narrows of the Hoback above as far as 
could be seen; but there are no conspicuous developments of red-colored 
strata along this part of the course of the Hoback, or between the caiion 
and the Snake. On the contrary, as has already been stated in relation 
.to the valley of the lower south tributary of the Hoback, lying between 
the Hoback Canon and John Day ridges, the grayish deposits constitute 
an important stratigraphical feature in this part of the Hoback Valley, 
especially in the east flank of the John Day ridge. Indeed, these deposits 
may appear in the topographical crest of this ridge towards its northern 
extremity. 
In the angle between the confluence of the Snake and Hoback, a rather 
high ridge abruptly terminates, which forms a sort of long spur descend- 
ing from the Hoback Canon ridge north of the latter stream, the termi- 
nal point overlooking the Snake Valley having a relative elevation of 
about 1,600 feet. Ascending to the summit there appear in the upper 
part of ‘the west slope exposures of gray and slightly reddish tinted, 
coarse-grained and shaly sandstones, interbedded with more or less i in 
durated drab clays, dipping variably northeastward at angles of 16° to 
25°. The sandstones hold indistinct plant impressions, and are in all 
respects identical with the great series that reaches up on the east flank 
of the John Day ridge. The inclination of the strata at this locality 
shows alow anticlinal, of which the present exposures form the east slope. 
To the eastward, along the summit of the ridge, newer deposits succes- 
Sively appear, maintaining an easterly inclination, and reaching over to 
the Hoback Canon ridge where they abut against the Carboniferous, as 
has been already noticed. 
The Hoback is here a fine stream, about 50 yards wide, with a brisk 
current of sweet, limpid water. Looking down upon the shadowed pools 
from the adjacent hills, the water has a beautiful green reflection. The 
stream bed is paved with water-worn boulders and pebbles identical with 
the materials found in the bed of the adjacent Snake River. The gravels 
in the river side afforded Mr. Perry a few scales of gold. In this connec- 
tion may be mentioned the faperable facilities for placer prospecting 
along the river, banks in this vicinity. The sandstones and clays incline 
in such way as to present their eroded, planed-off edges to the current 
of the ancient stream, like natural rifles, to retain the auriferous par- 
ticles borne along by the flood. On the west side of the Snake, a mile 
below the mouth ‘of the Hoback, a lively little stream emerges from the 
mountains clustered around Mount Baird, in the Snake River ran ge, its 
lower course broken into a series of beautiful cascades. Where it crosses 
the terraces in the valley it might, perhaps, be easily utilized in sluicing 
operations, though it is to be hoped SO beautiful a Spot may never be 
invaded by the chaotic ruin which placer mining entails wherever profit 
may be gained from the washing of the soil. The elevation of the v alley, 
about 6 ,000 feet, may not conduce to exceptionally favorable conditions 
for agriculture, but the valleys and adjacent hills are well stocked with 
grasses, and no doubt the hardier farm products would thrive. 
