186 



THE AUKIFEROUS GEAYELS OF THE SIERRA NEVADA. 



for the special purpose of making out, more satisfactorily than had been pre- 

 viously done, the position and direction of the channel in that vicinity: — 



( 



- 



have also the following : To the west of American Hill 



Among those interested in hydraulic mining at Nevada City there has been considerable differ- 

 ence of opinion concerning the probable original course of the old gravel channel. It is certain 

 that there is a deposit of gravel on the southern side of the Sugar Loaf, extending from the Muu- 

 zanita Diggings to and beyond American Hill, for a distance of a mile and a half or more, in a 

 general west by south direction. It is also known that there is gravel under and crossing the 

 Washington Ridge (the top of which is clearly an old lava How) ; for between the Kansas shaft, 

 on the northern side of the ridge, and the Manzanita Diggings there has been underground connec- 

 tion made for a distance of a mile or so. To the north of the Sugar Loaf there is about a squar 

 mile of country where there have been extensive surface diggings and where there are still one or 

 two larger isolated banks of gravel or pipe-clay. To the west and northwest of Sugar Loaf the 

 same lava flow continues, and is known as Cement Hill for a distance of two and a half or three 

 miles, to a point between Native American and Know Nothing ravines, where it comes to a sudden 

 end or has been cut off by the South Yuba. Under this Cement Hill lava there is also gravel, as 

 is proven by the prospecting at Dean's Tunnel and at Peck's Diggings (Rolfe and Stranahan), to 

 which reference has already been made. So much is positive ; in the shape of negative data we 



or Red Hill, a point a little farther west 

 than American Hill — down the present valley of Deer Creek we find but little if any trace of old 

 channels; beyond Peck's Diggings in Know Nothing Ravine there was never much gold found, 

 and to the west it is entirely a bed-rock country with no traces of gravel for some miles at least, 

 not, at any rate, until Rush Creek is crossed. Whether the main mass of lava of the Washington 

 Ridge covers a gravel deposit or not I cannot tell with certainty ; my explorations did not lead 



me any great distance up that ridge. 



The problem to be solved is, how are these different deposits of gravel to be connected 1 One 

 theory advanced was that the Manzanita Diggings are a part of an old channel which came down 

 from the north — from the neighborhood of Montezuma Hill ; another theory, based upon the sup- 

 posed higher altitude of the bed-rock at Peck's Diggings, supposed that the north and south chan- 

 nel came around by Peck's and thence to the Manzanita ground ; while others think that the old- 

 channel came from a nearly easterly direction (under the lava of the Washington Ridge, or not, as 

 the case may be) and continued to the west under the lava of Cement Hill. Neither of these 

 theories seems to be entirely satisfactory. Against the general theory of a channel flowing south 

 through this part of the country may be urged the general east and west course of the lava 

 flows, — and that is the main argument that I can urge at present, for I had no opportunity of 

 visiting the region to the north of the South Yuba at all, and have no direct means of knowing 

 what positive or negative evidence could be found there. Against the theory of the channel's 

 having come from Peck's towards the Sugar Loaf, I find the difficulty of the grade's being the 

 wrong way, to say nothing of the course of the old lava flow. Against the third theory, that the 

 Manzanita channel extended under Cement Hill towards Peck's, there is less objection to make. 

 To be sure the grade is almost too small, and it seems clear that a part of the channel at any rate 

 must have found its outlet by way of American Hill. Still, it is not impossible that there may 

 have been a forking of the stream from some cause or other, or a change of channel ; but if so, 

 I cannot believe that the two forks or channels ever united again near Nevada City, for to 

 do this one of them must have made a very sharp turn and returned almost along its original 



Without meaning to say that the problem is solved beyond all cavil, I am more and 

 more inclined to the opinion, the more I look at the subject, that there was an old stream or 

 ravine on the northern side of what is now Cement Hill, entirely independent of the one which 



course. 



came down on or nearly on the lino of the present Washington Ridge and discharged down the 

 line of the present Deer Creek. 



