The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1907-01-28
TESTS ON GOLD BARS.
Government Conducts investigation
on Snake River.

a report on placer claims above the
Minidoka dam on Snake river was re-
Gently made at the request OF the recla-
nation service by MessrS. l.. G. Gillett
and w. l.. Walker, under the direction of
DR.. David T. Day, of the United States
geological survey, and is now on file in
the office of the reclamation service IN
Washington, where any one interested
may consult il. The investigation OF this
ground was undertaken last May and
June in order to ascertain its mineral
value before II became submerged by the
backwater of the MinidOka dam. A plan
70 dredge this ground has lately received
considerable attention from promoters,
and already one company has been or
ganized and several claims near the lower
end of the backwater have been pur-
chased with view to the installation
of dredge.
The claims prospected were those des-
ignated by y. w. Ross. supervising engi-
neer OF the reclamation service. and were
situated along the Snake river above the
MinidOka dam. which is six miles south
Of the station Of Minidoka. Idaho. AS the
water was already rising when the in
vestigation began. the bulk Of the work
was done in the near neighborhood of the
old workings in order TO determine the
value Of the ground that was formerly
considered profitable, and to determine
whether the claims made were true The
values were found TO be very irregularly
distributed and in but few cases equal TO
| the claims made by those interested in
the land.
Many Test Pits Sunk.
The prospecting was accomplished by
means of test pits, panning and sampling
the samples being SHIPPED TO Portland,
Ore, for treatment and assay. The num-
Der Of test pits dug was 129. The in
formation gained b.: the field tests and
assay OF samples is rot such as to place
esm BUT the Pesufs derived er eiys tS
average values carried by the grounds
over which the pits were distributed.
These pits were so located as to repre-
sent the gravel bearing portions of the
claims. and those in the banks adjacent
TO old workings are OF special value be-
ing indicative OF the character and value
of removed material upon which holders
may base their claims.
Gold Is Fine.
1t was found that in general the values
were concentrated in the bottom OF the
! loan and the upper portion of the under
lying gravel. and the pits were carried
several feet bel4w this so-called pay
dirt" This surface soil or sandy loan
is common and ranges in thickness from
two TO twelve or more feet. The gold
was everywhere of such fine flour-iike
particles. that large percentage of it
passed through a l50-mesh screen, For
each pit a record was kept. showing the
nature of the ground and the results of
the panning. Samples weighing from 70
to 100 pounds. representative OF the
Withdrawing. gravel, were taken from
the loan and the gravels below the pay
dirt These were shipped TO Portland
for treatment, and the results OF the as
says are given in this report.
Range of Values.
Occasionally the values for individual
pits averaged for the entire pit as high al
Ss.31 a cubic yard, but the more common
values ranged from five TO twenty cents
cubic yard while very few pits were
absolutely barren of values. No other
minerals OF any commercial Importance
save gold were found
In most places nothing was encoun-
tered TO interfere with dredging or other
mining operations. The rocks are in gen
eral no larger than a mans head al
though in few places rocks large enough
TO make trouble were found
An examination Of topographic maps to-
gether with tho logs of the pits will indi-
cate for the various locations the eleva-
ton OF the gravels above normal water
level, or above the high water level re-
sulting from the dam baclxwatcr.