458 



SUPPLEMENTARY INVESTIGATIONS IN THE GRAVEL REGION. 



y 



in gravel. In the uncompleted air-shaft there were thirty-three 



lava, 680 feet ; hard rim-rock, .300 feet ; soft rirn-rock, 200 feet ; clay, 700 feet For the last 1,700 

 feet the tunnel has been entirel 

 feet of gravel. Above the gravel the shaft has been in clay for 142 feet. When finished, the shaft 

 will be 352 feet deep. The gravel seen in the tunnel was a good clean quartz, carrying some charred 

 wood and some poor impressions of leaves. I tried to secure some good specimens to show the 

 character of the vegetation, but ivas not successful. 



I have now traced the old channel from Council Hill to Potosi. In what direction shall I look 

 for its higher sources'? I am not at all satisfied with the evidence advanced in favor of the theory 

 that this channel came from the direction of Pilot Peak and Alturas, — the theory evidently enter- 

 tained by Mr. Hendel at the time of the preparation of the report from which an extract is given 

 on a previous page * It is true I did not examine in detail the whole of the ridge between Potosi 

 and Hepsidam ; I only followed the wagon-road between the two places. But I made frequent 

 inquiry of such miners as seemed to have the most thorough acquaintance with the whole district, 

 and, as a result of these inquiries, combined with my own observations, making proper allowance 

 for any warping of the judgment due to considerations of personal interest on the part of those 

 from whom I sought information, I am inclined to the opinion that the gravel channel will be 

 traced from Potosi through the ridge to its southeastern slope above Poker Flat. The only piece 

 of direct evidence that I have, which bears upon this question, is the altitude of the mouth of an 

 old tunnel, which is to be seen a little to the south of the. Poker Flat road. I made the altitude 

 to be only 5,526 feet, or nearly thirty feet below the mouth of Bonanza tunnel and fifty feet below 

 the gravel at the present farther end of that tunnel. When making this measurement I had not 

 heard of the Cold Canon mines, and had nothing to guide me to the proper spot at which to take 

 the observation. But whether I stumbled by accident upon the old tunnel through which the 

 Cold Canon gravel was worked or not, the parole testimony goes to show that in the Cold Canon 

 mine the bed-rock had a dip towards Potosi, and that the mine was abandoned only when the 

 accumulation of water in the drifts made further work unprofitable. 



But if the channel is traced to Cold Canon, what then % I cannot answer the question. Stand- 

 ing at the mouth of the old tunnel, one has before him the rough, jagged, open amphitheatre of the 

 head of Canon Creek, the opposite side of which he scans in vain for any indication which shall 

 guide his future search. As upon the ridge above Hepsidam, so here, I reached a limit beyond 



There is gravel on the opposite side of Canon Creek, which will be de- 

 scribed in the next subsection, but I cannot see any connection between it and the gravel of Cold 

 Canon. 



The total fall between Potosi and Council Hill is nearly 1,000 feet ; the distance is not far from 

 thirteen miles. The average grade, therefore, is about 122 feet to the mile. This grade is a few 



which I could not go. 



feet less than the average grade of Slate Creek between the bridge on the road from Potosi to Gib- 

 son ville, where the altitude is 5,480 feet, and the Poverty Hill trail at the mouth of Rattlesnake 

 Creek, where the altitude is only 4,000 feet. Taking the distance as eleven miles, the grade is 

 nearly 135 feet to the mile. The altitude of the bed of Slate Creek at the bridge, on the road from 

 La Porte to Port wine, I made to be 4,318 feet. 



The tailings in Slate Creek, which have been accumulating for so many years, must be very rich 

 in gold. The appliances for saving gold in this vicinity have been by no means so efficient as 

 those in use in the more southern counties, and the average yield of the gravels has been much 

 more to the cubic yard washed. At some time in the future a large profit may be expected from 

 them. A specimen taken from the Slate Creek tailings showed partially amalgamated gold. 



Upon the southeastern slope of the ridge, below Poker Flat, there are deposits of gravel, as at 

 Wahoo, for instance, which would have been examined had time allowed. Their relations to the 

 other gravels upon this and other ridges have not yet been well made out, and I must dismiss them 

 with this simple allusion to their existence. 



* See ante, p. 211. 



/ 



V 



