The Parker post., 1912-05-11
YUMA COUNTY
DRY PLACERS
DRY PROCESS PERFECTED TO
WORK DESERT GRAVELS.
Reduction Plant With Capacity of
1000 Cubic Yards Will Be In
stalled Near Quartzsite.

In the early days of mining in Ari-
Zona during the years from the COS
to the SOS a section of Yuma coun-
! ty known as the Plomosa, La Paz
and Middle Camp diggings, consider
able gold was taken from the gravel.
The methods used in gulch and gra-
vel mining were crude indeed, and
only rich surface values obtained,
leaving much wealth i'm the waste
and old dumpings
Prospecting of the Plomosa plac-
ers, during recent years has proven
them to be of unusual richness. They
are located in Posas valley, a great
north and south depression, with the
Plomosa mountain forming the east
ern border; with the northward ex-
tension of the Castle Dome range on
the west This valley extends north
ward for so to 40 miles and is from
10 to Is miles wide, and affords an
extensive field for placer or gravel
mining. On the eastern side of
this valley is the Plomosa placer
and the western an extended depos-
it of gold bearing gravel, in various
parts, known as La Cholla, Orc FinO
and Middle Camp diggings. In some
localities pits have been sunk to
depth of 20, 80 and so feet to beds
of GENE MT, which are richer than
the gravel. Miles of the great de-
posits extending westward from the
mountains, form deep ravines, and
they afford miles of bank 10 to Is
of gravel are well exposed. From
these banks samples taken by
mining engineer, who has thorough
lly investigated the entire section,
gave an average return value of "a
cents per cubic yard None of the
samples were failures A dry wash
means of rotary fan, which blows
under a fine screen, over which the
same passes in a fine stream. Re
suits lay between the extreme of AZ
cents and $1.04 per cubic yard. The
| limit of gravel actually explored was
2400 feet by 1900 feet and feet in
depth, and about the center of the
whole gravel tract extending 2 miles
each way east and west from it and
21a miles south and half mile north.
Across the valley IL miles from
the Plomosa placer, is another bed
of gravel of similar extent and of
high quality. This western mass of
gravel is occupied at various places
by three camps, all rich in gold, and
all differing materially in character
of the gravel.
Middle Camp, the most northerly
of the three, has granite; Orc Fino,
in the center, has much porphyritic
slate, very rich, and also very hard
and requires to be broken to powder
before going to the dry washer.
The locality of these placers is
among the oldest known portions of
Arizona. Forty years ago the Colo
freight for many years entered this
way, and the values of these placers
were we'll known to Miners who, in
that day passed over all the region
adjoining the Colorado river. The
absence of water in the mountains
compelled the miners to pack their
rich dirt to the river, or distant wa
ter tanks, to be washed. Trego on
the northern slope of Middle Camp,
has the distinction of producing the
purest gold of the whole country, sell
ling at $40 an ounce in the field. To
develop and obtain the gold from the
immense volume of gravel mentioned,
operations must necessarily be con-
Quoted ON a comprehensive scale
and as mammoth proposition. The
results obtained from the dry-waSher
methods give encouragement, look
ing to a grand success with machin
cry adapted to the separation of the
gold, black sand, platinum and other
metals of these vast placer lands,
without the use of water
For more than two years, Col. F.
w. Dunn and H. j. West have been
untiring in efforts to produce what
may be termed a dry process, to
successfully work the desert gravels
and cement-camying gold value. 1t
is the general belief they have been
eminently successful and with Bos-
ton men organized the Yuma Con-
solidated company. After organic
Continued on Page 4.