GRAVEL AND VOLCANIC FORMATIONS: IN PLUMAS COUNTY. 217 
the tunnel, as well as a ground-plan of the locality, which are reproduced 
on Plate K. There is a thickness of from sixty to eighty feet of detrital 
material, covered by a mass of volcanic “cement,” breccia, and tufa, which 
when least eroded away is about a hundred feet in thickness. At the bot- 
tom of the detritus is a thick bed of pipe-clay with impressions of leaves, and 
over this several alternations of gravel and sand (as shown on the section), 
one of the strata of coarse gravel containing some gold. It is not likely, 
however, that mining ever was, or could be, successfully carried on at this 
locality. Of the theoretical bearings of the fact of the existence of these 
deposits on Spanish Peak and Clermont more will be said in a future chapter. 
There is a gravel deposit of considerable extent at a point on Spanish 
Creek, above four miles west of Quincy, where considerable work has been 
done, although nothing could be ascertained with regard to the produe- 
tiveness of the material. From the large amount of washing which had 
been done here previous to 1866, it would appear that the undertaking had 
been profitable. The thickness of the gravel was about seventy-five feet, and 
it was quite homogeneous in character from the surface down to the bed- 
rock. The locality has an elevation of about 400 feet above Quincy, which 
itself is 3,270 feet above the sea-level. Consequently this gravel is about 
3,400 feet below that on Spanish Peak. 
No extensive gravel deposits were being worked in 1866 in Plumas County, 
north of the Middle Fork of Feather River, so far as the writer’s observation 
extended. In later years, according to Mr. Skidmore’s reports to the Com- 
missioner of Mining Statistics, there have been some undertakings of consid- 
erable magnitude commenced at various points. One of them is said to be 
situated “near Quincy,’ where the Hungarian Hill Company was at work 
in 1873, preparing to introduce all the modern improvements in hydraulic 
mining. This locality, the exact position of which is not specified, may be 
the one mentioned just previously. At Ohio Creek, a small tributary of the 
North Fork of the Feather, which enters that stream about six miles below 
the lower end of Big Meadows, a dam has been built, for the purpose of get- 
ting the necessary power to pump water up to an elevation of 328 feet, into 
reservoirs, for the purpose of washing a (placer?) deposit of gravel said to be 
very rich in gold. 
Fourteen miles east of Quincy there is said to be an important placer-min- 
ing claim, which from the description given must resemble in character the 
so-called “ seam diggings,’ previously mentioned as being extensively worked 
