300 GEOLOGY OF THE BLACK HILLS. 



and that it is extremely difficult to predict, even approximately, the value 

 of any particular <(ulch ov district until the gravel deposits have been com- 

 pletely opened and nearly worked out. 



The causes and circumstances which have influenced the concentration 

 of the gold in the placer gravels are but little understood, and erosion has 

 often removed entirely the ledges which were the source of supply of the 

 gold now found in the gulches. 



The deposits of auriferous gravel in the Black Hills may generally be 

 said to be favorably situated for working, and that the gold can be very 

 cheaply extracted, with the expenditure of but comparatively little time or 

 capital in opening the deposits. 



Compared with some of the world-renowned districts in California and 

 Australia, the placers at present discovered are not remarkably rich, yet 

 there are claims already opened and worked which are yielding a very good 

 return for the labor employed. 



At Cheyenne the railroad is not more than two hundred and fifty 

 miles from the gold fields; the roads over which machinery and supplies are 

 transported are excellent, the grades usually easy, and the drives not long 

 between water. 



The climate of the Black Hills is wonderfully healthy and invigorat- 

 ing; wood, water, and grass are everywhere abundant and of the best 

 quality. 



There is gold enough to thoroughly settle and develop the country, 

 and, after the placers are exhausted, stock-raising will be the great business 

 of the inhabitants, who have a world of wealth in the splendid grazing of 

 this region. 



