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mine managers of the several companies that carried out the work. Figure
23 shows the topography and surface geology of Slough creek and the lower
part of Nelson creek at the mine, also the locations of the principal bore-
holes, shafts, and tunnels. A cross-section of Slough creek at the mine
is shown in Figure 24. The subdivision of the surface deposits overlying
the bedrock, as shown on the cross-section, is based on the drilling records
as interpreted by the present writer and is somewhat generalized, as only
a few of the drilling records are available.

Mining development work at Slough Creek mine began in 1892 when
Charles Ramos, representing a company which had acquired a lease of part
of the valley bottom, put down a number of bore-holes and sank a 30-foot
shaft near the creek on the north side. The maximum depth of the channel
was determined at 246 feet, but this was later found to be incorrect. Three
bore-holes south of the creek (Figure 23), the deepest being only 45 feet,
were supposed to have reached bedrock, but it was proved later, when a
tunnel was run from the “gravel” shaft on the north side of Slough creek
to the mouth of Nelson creek, that large masses of rock or boulders were
mistaken for the bedrock and that the depth to bedrock at these places is
much greater. In sinking the gravel shaft trouble was experienced because
of the excessive pressure of the ground water. To overcome this difficulty
a drain tunnel 2,150 feet long was run. This, however, tapped the shaft
at a depth of only 37 feet from the surface. The drilling had apparently
shown that clay occurred at a depth of 45 or 50 feet and it was expected
that once the clay was reached the surface water could be shut off and the
shaft sunk through the clay to bedrock. No impervious clay, however,
was found, nor was it struck at a depth of 84 feet, which was the maximum

depth to which the shaft was subsequently extended. In 1895, the Slough ,

Creek Mining Company, Cariboo, of which W. H. Fife was president, took
over the property and continued the development work. Further boring
was done and the maximum depth of the channel determined at 287 feet.
A tunnel, known as the New tunnel, was started from the 37-foot level in
the gravel shaft and extended for about 825 feet to bedrock in the lower
part of Nelson creek, the bedrock at the end of the tunnel being about 80
feet below the surface. A hoisting shaft was put down at a point about
125 feet from the end of the tunnel and a crosscut at the end of the tunnel
was driven for 600 feet. One set of posts in the crosscut rested on bedrock
all the way and the bedrock was found to be pitching steeply into the
valley of Slough creek. Considerable difficulty was experienced in running
the tunnel because of the wet, caving character of the ground and because
of the large boulders encountered. It was found necessary to clean out
the old drain tunnel 30 feet above the new tunnel and to run a “balloon”
drive between the two to carry off the surface water. The tunnel was run
for the purpose of mining the bedrock gravels in the lower part of Nelson
creek and with the intention of sinking a shaft in the bedrock and drifting
out into the channel of Slough creek. Apparently no very high values
were found in the bedrock gravels of Nelson creek and the character of
the ground prevented sinking a shaft in the bedrock. In 1898 the property
was acquired by the Incorporated Exploration Company, Limited, of
London, England, which later became “Slough Creek Limited,” of which
William Thompson was managing director and consulting engineer, and