MINING. 293 
reaching over twenty miles, it still extends further. Hundreds 
of tunnels have been run in search of it. Where the line it 
follows was adhered to, they have always found it, and have 
been well rewarded for their labor. Millions of dollars have 
been taken from this lead, and its richness, even in portions 
longest worked, is yet undiminished. These tunnels have cost 
from $20,000 to $100,000 each, and interests in the claims 
they enter sell readily at from $1,000 to $20,000, in proportion 
to the amount of ground within them remaining untouched, 
and the facilities which exist for working it. Many of these 
claims will yet afford from five to ten or more years’ profitable 
labor to their owners, before the lead itself within them is 
exhausted. As in some of them quartz veins and poorer pay- 
ing gravel have been found, many of them may be valuable to 
work from the top down as hydraulic claims.” 
This idea that the blue lead occupies the bed of an an- 
tediluvian river is however not universally accepted. Mr. 
B. P. Avery, who has written numerous newspaper articles 
upon the mineral deposits, asserts that the “blue lead,” as 
it is called, is not a “lead” but an extensive stratum which 
is many miles wide, and is found all the way from the foot hills 
to the summit of the Sierra Nevada. In reply to this, it is 
said that while a bluish stratum of clay similar to that of the 
blue lead is found over a wide district, that it is evidently 
different ‘in origin from the blue lead itself, which is confined 
to anarrow bed, and marked by the signs found in all the other 
ancient river-beds of the state. 
The Sierra Butte Quartz Mining Company has some of the 
best auriferous quartz lodes in the state. One lode called the 
Cliff Ledge, is twenty-five feet wide; and another called the 
Aérial Ledge, is about three feet wide. In the Cliff Ledge, the 
paying rock averages about six feet in thickness next the foot- 
wall. The average yield is eighteen dollars per ton. The 
quartz is bluish-white in color, and very hard when first taken 
from the lode, but on exposure to the air it slowly crumbles 
into sand. 
