UNITED STATES GEOLOGICAL SURVEY
GEORGE OTIS SMITE, Director
Bulletin 592
MINERAL RESOURCES OF ALASKA
REPORT ON PROGRESS OF
INVESTIGATIONS IN
1913
The following are pages 363 – 369 of bulletin 592
PLACER MINING IN THE RUBY DISTRICT.
By Henry M. Eakin
FIELD WORK.
The Ruby district was revisited by the writer late in the summer of
1913, after a season of exploration in the Yukon-Koyukuk region.
Several days were spent in examining the active plants and gathering
data regarding the progress of mining since 1912. The success of
this brief visit was greatly enhanced by the operators and residents
of the district in their painstaking efforts to furnish exact data and
to extend courtesies and hospitality. Special.acknowledgment is due
Mr. Charles Forander, one of the original discoverers on Long Creek,
from whose records the data regarding production are largely taken.
PREVIOUS INVESTIGATION.
The Ruby gold placer district was visited bv A. G. Maddren in 1910
and by the writer in 1912. A summary of the geographic and geologic
data gathered in these years has been published,' and a more complete
report is in press.2 The present paper is intended only to
supplement the sections on economic geology contained in these
reports, so that the published history of the camp will include the
mining season of 1913.
GENERAL OPERATING CONDITIONS.
The population of the district has fluctuated considerably since
the fall of 1912 and has changed greatly in personnel. The general
trend is, however, toward a larger and more permanent population.
Labor has generally exceeded the demand at the current wages of
$5 a day and board. In some instances lower wages have been paid.
Freight rates have been lowered somewhat from those of 1912
owing to increased competition among steamboat companies. General
merchandise rates from Seattle to Ruby have been given as low
as $30 and $35 a top. Special classes of freight take rates 20 to 200
per cent above these figures.
- - - -
1 Eakin, H. M., Gold placers of the Ruby district and the Innoko-Id~tarod region: U. 8. Qcol. Survey
Bull. 642, pp. 279403,1913.
9 Eskin, H. M., The Iditarod-Ruby regon, Alaska: U. 9. Geol. Survey Bull. 678.
363
p364 MINERAL RESOURCES OF 'ALASKA, 1913.
Rough lumber has been reduced from $50 to $30 a thousand and
dressed lumber from $80 to $60. Cordwood varies greatly in price,
according to its availability. Many operators find it economical to
hire wood cut and hauled by the day instead of at a fixed cord rate,
the cost being lowered in some cases to $3 a cord. Extensive use
and forest .fires have greatly reduced the supply of fuel timber, so
that in future this element in the cost of mining will generally increase.
Transportation from l&uby to the creeks in the summer of 1912
took a rate of about $10 a ton a mile. In 1913 this rate was reduced to
$5 or $6 and even lower to some creeks. There was a corresponding
reduction also in winter freight rates. This decline is due in part to
increased competition in the business, in part to cheaper forage, and
ip part to improved roads.
An excellent Government road, used both in winter and summer,
has been built from Ruby for 3 miles toward the creeks. From its
end a winter road has been laid out over easy grades to the head
of Long Creek. In summer the same trail is used as formerly, and
it is for the most part extremely bad.
The water supply was exceedingly scant in 1913 owing to a prolonged
drought. This seriously handicapped mining throughout the
district, except the operation of plants equipped for pumping, and
curtailed the season's total production from what could have been
reasonably expected under ordinary conditions.
MINING.
ClENERAL ACTIVITIES.
Mining was continued in 1913 on all the six creeks that produced
in 1912, namely, Long, Upper Long, Midnight, and Trail creeks,
Bear Pup, and Glen Gulch. The industry was also extended to eight
other creeks of the district not previously productive-Lucky, Greenstone,
Monument, Ophir, Poorman, Duncan, Tenderfoot, and Tamarack
creeks.
CREEKS PREVIOUSLY PRODUCTIVE.
Long Creek.-Long Creek continued in 1913, as in 1912, to hold
h t rank among the creeks of the district in the extent of bown
placer deposits, the importance of mining operations, and the amount
of gold produced. The placer deposits of Long Creek below the
mouth of Bear Pup appare~tly form a fairly continuous pay streak
of variable size and richness. It reaches southward from the Cheyenne
fraction, at the Long Creek settlement, for a distance of about
5 miles to the Long Creek Association ground, where the mine farthest
downstream was located in 1913. The course of the pay streak is entirely
independent of the present stream and of the topography of
PLACER MINING IN THE RUBY DISTRICT. p365
the valley bottom. Consequently the depths of the mines vary,
the bench mines being deeper than those on the present stream bottom.
Considered in connection with surface elevations the depths
of the mines show that the bedrock surface has a greater slope down
the valley than the present flood plain. The Cheyenne fraction and
Windy Bench mines, for instance, which are on a terrace 30 feet
above the creek level at the north end of the pay streak, have depths
of 40 to 50 feet. About 5 miles down the valley, on the Long Creek
Association ground, is a productive mine whose shaft, starting at the
flood-plain level of the creek, penetrates 85 feet to bedrock. Still
greater depths are to be expected farther down the valley. In some
of the deeper holes the gravels are thawed and ground water has given
trouble. The deposits that may exist farther down the valley can
be exploited only at much greater cost and risk than those upstream.
The use of a drill in testing such ground is to be highly recommended.
The producti+e placer ground of Long Creek below the mouth of
Bear Pup is held in nine association groups of claims and four fractional
claims. Only one association group and two fractions were
idle in the summer of 1913. Thirteen plants, employing about 125
men in all, were operated. The plants varied in capacity, but all
were equipped with steam machinery that aggregated about 300
horsepower.
The winter work on Long Creek was confined chiefly to pruspecting
and blocking out ground. Five plants worked in a small way during
the winter of 1912-13.
Ppper Long Creek.--Claims Nos. 1, 2, 3, and 4 above Discovery,
on Long Creek above the mouth of Bear Pup, were worked during the
summer of 1913. During the previous winter the three claims above
No. 1 were worked in a small way. The hand windlasses used in
1912 were replaced by steam machinery, the four plants aggregating
over 100 horsepower. The later development work has shown the
gold-bearing gravels to lie in irregular bodies rather than in pay
streaks. This has required an unusual amount of prospecting, the
results of which generally have not been all that could be desired.
In places, however, very satisfactory ground has been opened. About
25 men were employed on upper Long Creek most of the summer and
6 men during the winter.
Bear Pup.--Claims Nos. 1 and 3 on Bear Pup were worked in the
summer of 1913. The gravels are but 12 to 16 feet deep, and the
mines are of the open-cut type. A single plant operated on each
claim. Both were equipped with heavy steam machinery that was
employed in scraping away the overburden, hoisting pay dirt to the
sluice boxes, and pumping water for sluicing. The two plants
aggregated 100 horsepower and employed 70 men continuously most
p366 MINERAL RESOURCES OF ALASKA, 1913.
of the summer. Rapid progress was made on both claims and the
results were very satisfactory.
No winter work is done on Bear Pup except prospecting and testing
values in known placer ground.
Midnight Creek.-As in 1912, but a single claim was worked on
Midnight Creek. A small steam plant, including a hoist, installed
on the Jennie Association ground the preceding winter, was operated
in the early part of the summer by six men. Later in the season
the force was reduced to two men, who continued work the rest of
the summer.
Although gold is widely distributed along Midnight Creek, the
development work done so far has failed to reveal concentrations rich
enough to yield much profit in mining. Very little prospecting has
been done away from the original discovery, however, and it may
be that the same effort spent in prospecting, especially in the lower
part of the valley, would yield better returns in tlie long run than
can result from the mining of such deposits as have already been
found.
Glen Gulch.-Mining on Glen Gulch was conhed to the operation
of three small plants, which were at a standstill most of the summer
owing to the water famine. Two of the plants did little besides
prospecting and the third took out a small dump during the summer
to be sluiced during the fall rainy season. Not more than six men
worked on the creek at any time. No winter work was done.
Trail Creek.-Trail Creek was unique in the district in the relatively
great extent of its winter mining. Four plants employing
16 men operated on separate claims most of the winter. Of these,
two were very successful, in view of the scale of operations, and made
considerable production. Early in the spring the mine farthest
downstream, 23 miles below Discovery, shut down, and another mine
was opened near the head of the creek, where some unusually good
ground had been discovered during the winter. Four plants, employing
about 30 men, were active throughout the summer. Owing
to the scant water supply part of the winter dumps remained until
late in the summer before they were sluiced.
The profitable mines of Trail Creek are all within 2 miles of the
head of the stream. The pay streak is narrow and fairly continuous.
It yields coarse gold for the most part. A nugget worth $296, the
largest yet produced in the district, was taken from the new mine
near the head of the stream early in the summer.
NEW PRODUCTIVE CREEKS.
Location.-Discoveries were made on eight new creeks in the Ruby
district during the winter of 1912-13 and the following spring. Four
of these streams are in the same general area with the creeks already
PLACER MINING IN THE RUBY DISTRICT. p367
producing. They are Lucky Creek, a westerly tributary of Flint
Creek next north of Glen Gulch, and Greenstone, Monument, and
Ophir creeks, which flow southward, the first to Long Creek, the
others to Solatna River, in the area east of Long Creek below Midnight
Creek. The other four new creeks drain an area that centers
about 30 miles south of the Long Creek diggings. Three of these,
Poorman Creek and its northerly tributaries, Duncan and Tenderfoot
creeks, belong to the Innoko drainage system; the other, Tamarack
Creek, heads against Duncan Creek and flows north to the Solatna.
Lucky Creek.-Lucky Creek is a small stream less than 3 miles in
length and having no important tributaries. Its deposits are adapted
for shallow drift mining, ranging from 16 to 30 feet in depth.
Two small plants, employing two and four men respectively,
prospected separate claims on the creek during the winter of 1912-13.
The work was continued during the following summer, but only a
small production is reported to have been made.
Greenstone Creek.-Greenstone Creek is about 5 miles long. It
heads in the same divide with Midnight Creek, near the same place,
and flows southwestward to join Long Creek a little above its mouth.
Shallow low-grade placer ground was located about 2 miles from the
head of the stream in the winter of 1912-13. The known placers are
all included in the Anaconda group-an association comprising four
claims. The ground is 3 to 12 feet deep and is easily worked by
open-cut methods. A single outfit employing five men worked
throughout the summer. Lack of water for sluicing hindered the
work greatly, but a profitable production was made. The cost of
working this ground could be greatly lessened by the use of machinery,
and in that case the outlook for the creek would be very encouraging.
Monument Creek.-Monument Creek is the next stream east of
Greenstone Creek. It is about 8 miles long and flows southward to
Solatna River. Good placer ground was discovered about midway
in the stream's course, at and below the mouth of a small westerly
tributary called Jack Rabbit Creek, during the winter of 1912-13.
Two plants, employing 17 and 5 men, respectively, were operated
the whole summer of 1913. The ground is 35 to 40 feet in depth.
It is well frozen, is adapted for economical drift mining, and is said
to yield very satisfactory returns.
Some prospecting was done during the summer about 2 miles
below the productive mines, and it is reported that pay dirt was
struck at this locality late in August.
Ophir Creek.-+hir Creek is the next stream east of Monument
Creek and, like it, flows southward to Solatna River. Two outfits
prospected on this creek in the early summer, one of which continued
work throughout the season. A rich discovery was reported
p368 MINERAL RESOURCES OF ALASKA, 1913.
and preparations for active mine development were under way the
last of August.
Poomn Creek and tributaries.-Poorman Creek is the extreme
northeastern headwater of the North Fork of Innoko River. It is
a stream of considerable size, being 20 to 30 feet wide and having
considerable depth and velocity at ordinary stages. It is reported
to have gone completely dry durisg the drought of 1913.
The geology of the Poorman Creek region is similar to that of the
district to the north. The formations include schists, slates, and
greenstones, probably of earlier Paleozoic age. Immediately south
of these rocks are cherts and less ahred igneous roch that may
- be considerably younger. The country is worn down to a very
low relief. The interstream areas are occupied by broad, smooth
ridges deeply mantled with products of rock decay and possibly in
some places with recent lacustrine sediments. The lower slopes of
the ridges merge with wide valley bottoms that are analogous 6
the alluvial plrrins of the lower Innoko. Both the ridges and the
bottom lands are timbered. The trees, mostly spruce and tamarack,
are for the most part of rather stunted appearance. Good-sized
trees are fairly plentiful, however, along thebanks of the streams and
at their heads.
The first prospects discovered in this region were taken from the
stream gravels of Poorman Creek in the spring of 1912 by Thomas
Armstrong at a point about 8 miles southeast of Twin Butte Moun-
. tain. Several holes were sunk to bedrock the following winter, and
on March 7, 1913, gold-bearing gravel was hoisted from a hole near
the original discovery by Armstrong and his partner, Gus Olson.
Since then a great deal of prospecting has been done in the region,
and valuable placers have been located at three separate localities
on Poorman Creek and on two of its tributaries, Duncan and Tenderfoot
creeks. The lowermost locality on Poorman Creek is about
1+ miles above the mouth of Tenderfoot Creek, and that farthest
upstream, 5 miles above, is near the mouth of Duncan Creek. The
locality on Duncan Creek is a mile above its mouth; on Tenderfoot
Creek, half a mile above its mouth. The deposits are much alike
wherever explored. Their depth ranges from 53 to 65 feet. The
gold lies in a stratum of gravel on bedrock, 3 to 6 feet thick. The
overburden is chiefly muck. The gold occurs for the most part
in fine shot-like particles and shows the effects of transportation in
wear and assortment. The widest crosscut in pay gravel on Poorman
Creek is 125 feet, in the mine near the mouth of Duncan Creek.
The development work done so far is not sufficiently extensive to
demonstrate the existence of continuous pay streaks on Poorman
Creek and its tributaries, but the evidence in hand all points in
that direction. If this should prove to be the case, a d if the width
PLACER MINING IN THE RUBY DISTRICT. p369
and richness of the deposits known to occur locally should prove to
be general, the production from this part of the district should quickly
assume large proportions.
ail[ining was done at times during the summer on Poorman, Duncaa,
and Tenderfoot creeks, five claims in d, each worked by a separate
plant. But little machinery had been taken iPto the region, so that
operations were necessarily conducted on a small scale. The miners
were further handicapped by aa. absolute lack of water for sluicing
during a greater part of the summer. About 15 men in all were employed
in mining.
Tamarack Creek-Tamarack Creek is about 8 miles long. It heads
agsinst Duncan Creek and flows northward to Salatna River. Prospects
were found on the creek during the spring of 1912, and pay
gravel was located the followihg winter at a locality about 3 miles
from its head. A small outfit employing four men worked on this
ground during the summer of 1913.
The r n h g industry in the Ruby district has shown on the whole
considerable advancement over the preceding year. The six streams
that produced in 1912 were worked again in 1913, most of them with
a largely increased scale of operations. The changes were brought
about mainly by the installation of heavy steam machinery in place
of the light hoists and hand windlasses used before.
Placers were discovered on eight new creeks, some of which are
very promising. Prospecting is being done on still other creeks,
and in places results are being obtained that suggest the likelihood
of a further increase in the number of producing creebs.
All told, there were 4 1 plants engaged in actuaI mining in the Ruby
district in the summer of 1913, operating 38 claims on 14 diffarent
creebs and employing a totd of about 230 men. Of the 41 plants
33 were equipped with steam machinery that aggregated over 750
horsepower. The other 8 plants used hand labor.
Dung the winter of 1912-13 twelve plants were operated onas
many claims situated on three creeks. About 40 men were engaged
on this work.
The winter production of the district amounted to $102,200.
Data regarding the value of the summer's production are incomplete
as yet, but it is estimated at $750,000.
60553°-B~. 592-14---24