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FROM FRENCH CORRAL TO NORTH SAN JUAN. 385 
the bed-rock. I place these in the same category for the reason that the ditches frequently give 
the best information, or the only information, in regard to the character of the rock beneath the 
surface. There are some errors — absolute errors —in the positions of the mining ditches, which 
arise from the incompleteness of the map ; and there are other errors in the relative positions of 
ditches and lava, the true correction for which cannot be easily ascertained. In this connection I 
will call attention also to a fertile source of doubt as to where the true bounding line of the vol- 
canic capping should be drawn. Thc sides of the cafons are sc steep that much of the loosened 
lava of the crest rolls or slides down to a greater or less distance and covers the bed-rock to a 
thickness varying with the local conditions. If we decide to draw the line in all cases at the 
lower extremity of these slides, the space on the map to be colored for lava will be very much 
larger than it would be if we conclude to disregard the slides altogether and attempt only to give 
the boundaries of the solid and compact lava — the lava ‘in place.” * 
In regard to yield of gold on this divide I will give Mr. Miller’s estimate. He places the pro- 
duction of the mines on the divide between French Corral and Snow Point for the year 1878 at 
$ 1,500,000. His facilities for gathering information are unusually good, and I place great con- 
fidence in his estimate. I made frequent inquiry for evidences of prehistoric man at several 
places on this divide, but could never hear of any evidence — even remote — that would lead one 
to suspect the existence of man during the gravel-forming period. 
In speaking of the Smartsville mines I referred to the fact that Chinese labor was not em- 
ployed. On the divide between the Yubas, however, I found Chinese employed in large numbers 
for certain kinds of work. Men who oppose any further immigration from China find their profit 
in employing the Chinese who are already in the country. 
The system of “ undercurrents,” which has been pushed to a great extent upon this divide, would 
be worth a careful study from an economical point of view, as one of the most approved means of 
reducing the unavoidable waste of gold. I visited the undercurrents at some of the mines, but did 
not take the time to collect data about them, or their real efficiency. The subject has received a 
good treatment, however, by Mr. Bowie. 
I will now take up the description of the different mining districts on the divide. 
A. From Frencu Corrat to NortH San JUAN. 
At French Corral I learned from Mr. N. C. Miller, Secretary of the Milton Co.,t+ of the existence 
of a ridge of gravel at a considerably higher altitude than that of the main channel, to which 
reference is usually made when speaking of the French Corral mines. This high gravel has never 
been worked to any profit, so far as I could learn; but efforts have been made from time to time, 
by the sinking of shafts and the driving of tunnels, to open up a paying property. That there is 
some gold to be found at this higher elevation seems to be beyond doubt; but the difficulty of 
procuring water for washing and the probably small quantity of gravel make it very unlikely that 
the yield or profits of working will ever amount to much. I tried to find some of the men who 
had formerly worked at this point, but was not successful. . All the information I have came from 
Mr. Miller, or was derived from a visit I made to the site of one of the old shafts one evening 
aiter sundown. Mr. Miller conducted me toa point known as the “coal pits,” the altitude of 
which above the bed-rock at the French Corral mines is about 550 feet. We were here upon the 
top of the ridge, near the mouth of one of the old prospecting shafts. The ridge referred to lies 
* The most serious errors of this class upon the divide between the Yubas are between Lake City and Eureka. 
I endeavored to find corrections for some of the errors, but now think it best to suggest no changes upon the 
lithographic stone, leaving them as they are, with a written explanation of the character of the inaccuracies, until 
further surveys of the territory in question can be made. 
+ I reached French Corral by stage from Smartsville, and presented my letter of introduction at once to Mr. 
N. C. Miller, the Secretary of the Milton Co. Mr. V. G. Bell, the superintendent, was not at home, and I did 
not see him at all. Mr. Miller was very kind and courteous to me during the tiie of my stay. 
