THE CHANNELS: IN PLACER AND EL DORADO COUNTIES. 107 
to pitch to the south. This is the only indication yet discovered of a northwestern rim to the 
great Forest Hill channel, and this is over a mile distant from the known position of the south- 
eastern rim. 
Something over a mile northeast of Bath, the mining operations have shown that the bed-rock 
rises quite high in the immediate vicinity of a deep channel. In the bottom of Volcano Caiion, 
at the crossing of the upper road from Forest Hill to Michigan Bluff, a shaft was sunk 153 feet 
deep through volcanic cement. Before reaching the bed-rock, and on the crest of the ridge, a 
quarter of a mile west of this, the bed-rock rises to an elevation of about 400 feet above the mouth 
of the shaft. At the bottom of this shaft the bed-rock was found pitching to the northwest, show- 
ing that they were on the southeast side of the lowest part of the channel. They then followed 
down some ten or twelve feet lower on the rock, and found the gravel very hard, but rich in gold. 
About half-way between here and Bath, and on the northwest side of Volcano Cafion, is the Maine 
Boys’ Tunnel, which was driven through very hard bed-rock, in a direction nearly north (magnetic) 
some 500 or 600 feet, and at its end broke through into what is believed to be the same channel 
as that reached by the shaft above described. They then went down with a slope on the surface 
of the bed-rock to a vertical depth of ninety feet below the tunnel before reaching the bottom of 
the channel, when the water drove them out. 
Near the northwest end of the tunnel in the Paragon Mine, at Bath, the pay streak and all the 
accompanying strata, so far as here prospected, above and below it are cut sharply off by a mass of 
volcanic cement precisely similar in character to the so-called “ gray cement” of the Deadwood 
Mines, which contains much partially carbonized wood and some metamorphic pebbles. On strik- 
ing this mass the tunnel was continued for about a hundred feet into it to the northwest, in the 
hope of passing through it and finding gravel again beyond it; but without success. The surface 
of demarcation between it and the elided gravel strata was however followed by drifts for a dis- 
tance of nearly 600 feet, and was found, though somewhat crooked, to have a general direction of 
very nearly east and west (true course) and a pitch or dip of about 45° to the north. There can 
be little doubt that this body of cement marks the position of a stream which, subsequent to the 
deposition of the gravel strata in the Paragon Mine, eroded a considerable portion of them, and 
then afterwards had its own channel filled with volcanic mud. And it is not at all improbable 
that it may have been the same stream whose channel was struck in the Maine Boys’ Tunnel and 
in the shaft in Voleano Cafion. If this be true, the general course of the stream was southwesterly, 
and it came from somewhere in the Michigan Bluff divide. 
The channel at Jones’s Hill, four miles northwest of Georgetown, appears to run very nearly west 
(magnetic) in the Columbia Mine, with a grade falling in that direction, heavy enough to make 
brakes necessary on the cars. The channel passes under the southern slope of the hill, and is said 
to range from fifty or sixty feet in width to over two hundred, averaging perhaps a hundred. It 
is described as well-defined, with a high and steep rim-rock rising on the north side, while the 
southern rim is not more than ten or twelve feet high. The channel has been followed and worked 
here, by drifting, for over a quarter of a mile ; it has generally paid well, and in spots has been 
very rich. 
In the Roanoke Tunnel, near Bottle Hill, the channel varied from ten to a hundred feet or more 
in width. The whole length of the tunnel through the hill was rather more than a mile, and it 
was somewhat crooked, although its general course was N. 50° W. (magnetic). The channel is 
narrow, and the rim-rock high on both sides, although it is not known how high. It is said, how- 
ever, that an incline was once run up on the northeast rim to a height of fifty or sixty feet above 
the tunnel, and that here an upper stratum of gravel was struck, which was about four feet in 
thickness, the bed-rock then remaining nearly level in a northeast direction, so far as it was fol- 
lowed, or for a distance of fifteen or twenty fect, indicating that the top of the rim had been 
reached. 
At a point where the channel in Roanoke Hill leaves the hill, a little side channel comes in from 
the south. This little channel, where seen by Mr. Goodyear, was not more than twelve or fifteen 
