FOREST CITY AND VICINITY. 



437 



bed-rock, that it seems clear there must be some foundation for the opinion in fact though I con- 

 fess I am at a loss for any rational explanation of the phenomenon. The lava mud-flow which 

 cuts out the gravel for a distance of 225 feet is evidently of more recent origin than the gravel is. 

 When the lava was struck, a prospect tunnel was run to the east, and drifts were carried to the 

 west, until bed-rock was reached rising very rapidly. Upon this bed-rock there was pipe-clay 

 and above the pipeclay lava. The main tunnel was finally carried across the lava with the same 

 grade that it had been having below, and the gravel was found on the opposite side in just the 

 position, with respect to grade, that the continuation of the lower gravel ought to have. Upon 

 both sides the gravel dipped underneath the lava. 



The gold found in the Bald Mountain gravel is very coarse. The same is true of the gold of 



the lower stratum at Chips's Flat, while that in the top gravel is fine. The secretary of the Bald 

 Mountain Company allowed me to select a few specimens, which show well the general character 

 of the gold. They were examined by Mr. Wadsworth, who says of them : " These grains are of 

 very unequal sizes. One contains portions of the quartz vein-stone and lias its edges rubbed down. 

 Another is thick and well rounded. One is flat, and either composed of two pieces welded to- 

 gether, or else of one part bent over and upon a portion of the remainder. Whatever may have 

 been the original form, if the gold was thin, it seems that it would easily be beaten into flat pieces 

 with rounded edges. One queer form resembles a dress-hook. It is composed of quite a long 

 narrow strip of gold, that is bent partly upon itself twice. It lias welded to it another smaller 

 piece of gold, and it is easy to see how under the grinding, pounding action of pebbles it would 

 form a rounded, thin gold grain." The fineness of this e 



a 



,old averages from .926 to .936. From 

 the books of the company I obtained a few statistics in regard to the yield of the gravel between 

 April, 1872, and July, 1879. The area worked amounts to about 1,500,000 square feet, and the 

 total yield of gold is a little over $1,500,000, of which $664,000 have been distributed as divi- 

 dends. The average yield per square foot has been $ 1.01 -|-. The averages per square foot in the 

 several years were as follows, $1.09, $1.01, $1,011, $0.95], $0.99|-, and $1.00. A yield of 



1.01 1 per square foot, with drifts three and. a half feet high, corresponds to $7.83 per cubic 

 yard. But according to the company's books the average yield per car-load has been $2.92. 

 Each car is estimated to hold about one cubic yard of loosened gravel and rock, or one-half a cubic 

 yard of rock in place. This corresponds, therefore, to a yield of $5.84 per cubic yard. These 

 two results do not agree as closely as could be wished, but they are sufficient to confirm the state- 

 ment that the bottom gravel is very rich. Probably the cars do not contain quite a cubic yard 

 of loose rock; their dimensions arc given in Raymond's Ileport for the year 1874, p. 155, as 



4 J feet long, 2 feet wide, and 2 J feet high." Assuming these to be the true dimensions, a yield 

 of $2.92 per car-load corresponds to a yield of $7.01 per cubic yard. 



The hauling of the gravel in the Bald Mountain tunnel is done by means of a locomotive 

 similar to those in use in the coal-mines of Pennsylvania. The anthracite coal used costs, delivered 

 at the mine, about $42 per ton. 



The grade of the Bald Mountain channel is so much higher than is usual in the old gravel 

 streams, that many persons have believed it to belong to some tributary, rather than to the main 

 channel or blue lead, and that its eoniinuation is to be looked for, not in the direction of Bock 

 Creek and City of Six, but under the lava ridge to the east and northeast. In this belief mining 

 claims have been laid out and explorations have been undertaken at several points higher up on 

 the ridge, and also, in the hope of striking the main channel, at points to the west of the Bald 

 Mountain mine. 



In the latter direction the most important and extensive explorations have been conducted 

 by the North Fork Company. A tunnel, of which the mouth is near that of the Bald Moun- 

 tain tunnel, but on the opposite side of the north fork of Oregon Creek, has been driven in 

 a general northwesterly direction for nearly a mile. A branch from the tunnel lias at first a 

 more northerly course, and then bears around to the west, in which direction it has been con- 

 tinued to and beyond the line of the first tunnel, and at a different level. There has been but 



