642 OREGON AND NORTHERN CALIFORNIA. 
hillocks lie within half a mile of the sandstone and serpentine hills on 
the west, and one was only a hundred yards distant. 
Such was our approach to the Shasty Peak. We entered the 
mountains the next day, and travelled along to the west of it, within 
fifteen miles of its base. The hills were trachytic, and blocks of this 
light gray rock lay piled on one another through the forests, or were 
raised in mounds and hills, and long low ridges. We observed, how- 
ever, no continuous bed of trachyte. The blocks were generally from 
six inches to a foot through. 
In one view, from the west, the steep and even slopes of a black 
“‘sugar-loaf” rose from a deep valley below us; it was one object in 
the distant prospect from the prairie, the day before. The top of 
this volcanic cone was a little broken, and probably contained a crater, 
though none could be seen from the direction observed. We 
estimated the height at three thousand feet above its base, or four 
thousand five hundred feet above the sea. The sides were enveloped 
in pines or cedars, except about the summit, where only afew stinted 
trees made out to grow. 
The trachyte had the usual rough fracture and feel of this rock. It 
was generally compact; yet some blocks were minutely cellular, and 
a spongy variety approached pumice, though no specimens of true 
pumice were seen. On decomposition it forms an ashy dust, which 
flies like dry ashes on riding through it. In some instances burning 
timber had changed the gray colour to a faint reddish tinge. 
The appearance of the Shasty Peak has been already described. Its 
summit had been so much broken and denuded since the period of its 
activity that the crater features were mostly lost. ‘The higher peak 
may have been the original crater; and there appeared to be a de- 
pressed plain at its summit. The lower peak stands a little like 
Vesuvius in the arms of Somma, and may have been the site of later 
eruptions. No time was allowed for closer exploration, as the party 
continued its course without stopping. ‘The slopes in the distant view 
appeared to be covered with loose fragments, and had the light gray 
colour of the trachyte seen on our route. The ragged walls that pro- 
ject above the surface on the southwest side of the higher peak, ex- 
tending down its steep sides through three or four thousand feet, are 
probably the lines of fractures or the courses of dikes. The long 
shadows of the needles and long points of rock in these walls, showed 
that they project to a great height, probably at least five hundred 
feet. 
