MINING. 291 
principal mining towns are Downieville, Monte Cristo, Pine 
Grove, St. Louis, La Porte, Poker Flat, Eureka City, Forest 
City, Alleghany Town, and Cox’s Bar. One of the most re- 
markable features of the placers of the state is the blue lead, 
which was first discovered in Sierra county, and has been more 
thoroughly examined there than elsewhere. The “blue lead” 
is a stratum of blue clay very rich in gold. _ It is found deep 
under other strata. The general opinion is, that the blue lead 
occupies the bed of a large antediluvian river, which ran parallel 
with the Sacramento and about sixty miles eastward of it. It 
has been traced twenty miles or more, passing near Monte 
Cristo, Alleghany Town, Forest City, Chip’s Flat, and Zion Hill. 
Mr. C. 8. Capp wrote thus to the San Francisco Bulletin: 
“ This is not one of the many petty leads, an inch or two in 
breadth and thickness, which, afler being traced a few hundred 
feet, end as suddenly and mysteriously as they commence ; but 
it is, evidently, the bed of some ancient river. It is often hun- 
dreds of feet in width, and extends for miles and miles, a thou- 
sand feet below the summits of high mountains, and entirely 
through them. Now it crops out where the deep channels of 
some of the rivers and ravines of the present day have cut. it 
asunder ; and then, hidden beneath the rocks and strata above 
it, it only emerges again miles and miles away. Wherever its 
continuity has been destroyed, the river or gulch which has 
washed a portion of it away, was found to be immensely rich 
for some distance below, and the materials of which the lead is 
composed are found with the gold in the bed of the stream. 
It is evidently the bed of some ancient stream, because it is 
walled in by steep banks of hard bed-rock, precisely like the 
banks of rivers and ravines in-which water now runs, and be- 
cause it is composed of clay which is evidently a sedimentary 
deposit, and of pebbles of black and white quartz, which 
could only be rounded and polished as they are by the long- 
continued action of swiftly running water. The bed-rock in 
the bottom of this lead is worn into long smooth channels, and 
also has its roughnesses and crevices like other river-beds. 
