The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1919-01-30

'HSAhNNi III Aldi
The Roosevelt tunnel is the latest
and most important of the numerous
tunnels driven through the surround
ing Cripple Creek mining district.
Most of the previous tunnels were
driven primarily for exploration pur-
poses, but the Roosevelt tunnel has
been intended chiefly for drainage.
The FL Paso tunnel, driven through
the surrounding granite walls into
the eruptive rock or the Cripple Creek
volcanic crater, would effectually
drain large part of the productive
area, down to the tunnel level.
Portal 1898 Feet Above Sea.
Accordingly after many delays and
several expensive attempts to lower
the water level by pumping, the
Roosevelt tunnel was begun in June
1907. The point selected for the por
tai is in Cripple Creek gulch, about
five miles to the southwest of the
town of Cripple Creek 1t is at an
elevation of S03S feet above sea level
and the most favorable point for a
tunnel of the length decided. Work
was continued with several long in
tervals of suspension up to the pres
ent time. The total length of the
main bore is now 24,255 feet The
face is near the center of the Hawk
eye claim of the Portland Gold Min
ing company on Battle mountain. The
section for nearly the entire distance
is to 10 feet wide and 7 feet high.
The grade is 03 per cent or a rise of
8 feet per 1000 for the entire distance.
The elevation at face is approXim-
ately S110 feet above sea level. A
waterway at one side is provided 4
feet wide by feet deep
THE total costsof the main bore up
to August l. 1918, when work was
suspended amounted to $S12,000 This
included the cost of sinking an inter-
mediate shaft roo feet deep and a
raise to the bottom of the Elkton
shaft of 100 feet. This would make
the average cost $3.50 per lineal foot.
The highest cost per foot for any one
month was $1O6 and the lowest $13.
1.-THE Roosevelt tunnel has lowered
the general underground water level
of the district some $50 feet. Careful
measurements of the flow at the
portal have been made every month
The maximum discharge observed
was 1900 gallons per minute, which
continued for several months during
the early part Of 1916. 1t has now de-
clined to some $500 gallons per min
ute. The total discharge divided by
the total vertical subsistence Csc
! feet) indicated that there was pres
ent in the area drained 40,O00,OO0 tc
/ $4,000, 900 gallons of water per verti,
cal foot.
at has been estimated that to low
er the water level by pumping woulc
have cost $4,000 per vertical foot. Up
on that basis the Roosevelt TUNE
has saved the mine owners of tht
district fully $3000,000 to say moth
ing of other benefits and its useful
ness will continue for many years t.
come. Mining operations above tn
tunnel level will never again be seri
ously hampered by water Shaft
sunk below the tunnel will no dout
encounter considerable water, but
will not have to be raised 1000 fee
or more to the surface. The tunnt
!. has been connected by raises wit
/ four of the principal shafts, the +
Paso, Elkton, Cresson and the Port
, land. Several important laterals hav
also been driven. The Fuller cross
cut in the Ell Paso ground 100 fee
[ long, the Raven Beacon Hill dri1
f about 800 feet long, the Cresson lat
| eral some 1900 feet long connectin
with the Cresson main shaft at
depth of 1920 feet and the Portlan
lateral connecting with the Portlan
No. 2 shaft at a depth of 2133 fee
and about 1000 feet long.
Cut Rich Ore Veins.
quite a number of veins and dyke
have been cut in the tunnel. OF thes
, at least three carry good ore Wher
encountered. In the Cresson laterS
large body of good ore was opene
about 400 feet south of the shaft. Tn
ore shoot is now being developed wit
very encouraging results. A vein
high grade ore was also cut in tn
Portland ground not far from the N
9 shaft In the Rose Nichol propert
vein was cut about 60 feet east
- the shaft yielding good pay ore Man
!. of the other veins opened carry To-
grade ore and will undoubtedly be eX
plored at some future time when con
ditions are more favorable.
!, "The Roosevelt tunnel may now /
, considered complete 1t has accom-
: plished all that was expected of
:. and has fully justified the expenditul
;, for its construction. The discovery
large and rich ore deposits in tt
tunnel at depth of 1000 feet or moi
should encourage deep mining in II
district. In this connection it is on
fair to state that much credit is dl
A. e. Carlton for the energy and pc
sistence with which he has supportt
this great enterprise from the begil