504 THE VICINITY OF PLACERVILLE. 
cutting deep enough to take them all away, and isolate greater or smaller patches of them here and 
there, thus giving origin to those curious lenticular masses, like the heavy one of white lava, 
which has .already been entirely washed away in the hydraulic work at Coon Hill. 
The channels so excavated were subsequently filled, either with similar material, or with 
gravel, or with a different kind of voleaniec matter, and so the long work went on. After 
the white lava had ceased to gather, then came to Placerville the mountain gravel, the streams 
which brought it excavating also to a greater or less extent their own channels through the 
previously accumulated matter, gathering their own materials from the dark-colored compact vol- 
eanic rocks, which had made their appearance higher in the mountains, grinding a portion of 
these materials to powder, rounding and smoothing the rest to a perfect gravel, and picking 
up occasionally a pebble of quartz or granite or slate by the way, and finally piling up all this 
stuff, to depths sometimes of a hundred feet. Lastly came the successive deluges of black lava, 
or voleanic breccias, which overspread the whole, and crown the highest crests of the modern 
hills and ridges. 
Such seems to be the outline of the most prominent features in the history of the gravel hills of 
Placerville. The vast complexity of their detail forms a labyrinth whose windings it is hopeless 
to expect will ever be completely traced, and whose history, if fully known, it would probably 
require many a ponderous volume to relate. 
Yet the general modus operandi of their formation seems evident; the order of succession of the 
leading kinds of material which form the great mass of the hills is also seen, and the general fact 
seems clear that these materials came from the northeastern country, which formed then as now 
the higher portion of the mountains. And, though the order of succession of the different kinds 
of material is sometimes different at different localities, and there is no end of variety in the de- 
tails, yet in all the facts last stated, that is, in almost all the leading, general features of the sub- 
ject, these hills of Placerville present an epitome of the whole gravel region so far as I studied it 
in 1871. 
There is a range of country running from near the South Fork of the American at the mouth of 
Webber Creek, and passing just west of Shingle Springs in a direction a little to the east of south, and 
passing just east of Latrobe to the edge of the caiion of the Cosumnes just below the mouth of Big 
Caiion Creek, which is so high that I do not believe it has ever been crossed by any of the large 
streams coming from the mountains above. And I think there is far more probability that the 
South Fork of the American may once have crossed the ridge at Centreville and joined the North 
Fork higher up than now, than that it ever found its way to the valley as a separate stream. In- 
deed, it seems but natural that, when the locality of the junction of two mountain streams is 
shifted, it should be changed to points lower down the mountain slope rather than to those which 
are higher up. Such seems to have been the case at Forest Hill, and such may very possibly have 
been the case here. 
The immense quantities of gravel and other river débris accumulated in the vicinity of Folsom 
speak volumes in favor of the idea that the débouchement of the American River from the moun- 
tains has never since the earliest gravel period been far from where it is to-day ; while the absence 
of any corresponding quantity of similar materials between these and the vicinity of Michigan Bar 
is equally strong evidence that since that time no very large stream has reached the valley at any 
point between the débouchement of the Cosumnes and that of the American. 
I can probably add little of any moment to what is given in the detailed notes respecting the 
region I traversed in going from Placerville, via Fairplay, Grizzly Flat, Brownsville, Indian Dig- 
gings, Voleano, Fiddletown, Mnd Springs, and Latrobe, to Michigan Bar. It will be seen that in 
the country passed over on this trip, from Fairplay through the localities named to Fiddletown, 
there are great quantities of volcanic matter, and in places considerable gravel beneath it in the 
ridges. But I have been able to trace no definite channels here. I saw nothing, however, to 
conflict with the theory that the general course of the streams was southwesterly here as well 
