bt.joks.] VICINITY OF TOGWOTEE PASS. 473 



when viewed at a distance ; the red lava forming the principal material 

 in the great debris slide in the east face of the mountain. In the lower 

 portion of this slide fragments of a more compact trachytic variety of red 

 lava were found. In outlying ridges, at the foot of the steep ascent, a 

 grayish, thin-bedded, slaty volcanic rock occurs, the ledges much dis- 

 turbed, being tilted in various directions. Near by large masses of dark 

 rusty volcanic rock occur, which may be the same as that forming the 

 level crest of the flanking ridge. These data furnish conclusive evidence 

 of the volcanic character of an extensive belt along this part of the 

 watershed ; just how far to the southeast it extends, I cannot say, though 

 it is my impression that it reaches in that direction more than half the 

 distance from Togwote Pass to the Warm Water or Union Pass. 



An arm of what may be termed the Togwote Mountains, comprising 

 the volcanic-capped watershed between Buffalo Fork and the extreme 

 eastern sources of Snake River and the Wind River drainage, which 

 reaches westward into the depression east of Buffalo Fork Peak, shows 

 the volcanic breccia deposits gently uplifted, as though they had par- 

 taken to some extent in the upheaval which brought to view the Ar- 

 chaean rocks in the Buffalo Fork quaquaversal. Looking northeastward 

 from Buffalo Fork Peak, further evidences of disturbance are noted in 

 connection with the volcanics that form the distant ridges about the 

 sources of the Yellowstone and Buffalo Fork, to the southeast of Two- 

 Ocean Pass. Dark banded deposits in that quarter, apparently vol- 

 canic, show a broad, shallow synclinal, the axis of which seems to run 

 in a southwesterly and northeasterly direction. But in the point be- 

 tween Lava Creek and Buffalo Fork, these deposits, appearing in gigan- 

 tic escarpments rising into high, bare mountain ridges and plateaus 

 encircling the ultimate sources of this drainage, are quite horizontal, or 

 but very slightly inclined in the exposed faces presented to view from 

 this direction. 



This whole region is one of most forbidding grandeur. The volcanic 

 crests all rise above timber-line, while their precipitous sides show the 

 dull banded volcanic ledges almost destitute of vegetation. But the 

 taluses are generally heavily wooded, and at the time of our visit 

 immense columns of smoke from forest conflagrations rose high in air, 

 in places blotting out the view of distant mountains. 



