MINOOK CREEK GROUP. 33 
Mining. — During the summer of 1904 work was being done on Discovery claim, 
about \\ miles above the mouth of the creek; and on No. 17, a claim about 4 miles 
above the mouth. Several claims between these were being prospected. 
On Discovery claim a flume 2,000 feet long, 30 inches wide, and 20 inches deep 
carried water to a bench about 16 feet above the creek. The bench was covered by 
5 to 6 feet of gravel and over this was 1 to 4 feet of muck. The muck and gravel 
were practically all sluiced off, and the loose bed rock in which the gold is found to 
a depth of about 18 inches, was shoveled into sluice boxes. The bed rock is partly 
a diabase and partly a much-folded brown, cherty shale standing on edge. The 
large bowlders were moved by hand. Three men ground-sluiced an area 75 by 150 
feet in thirty days. The gold is mostly bright, smooth "pumpkin seed," with a few 
small rough pieces (PI. VI.) A considerable amount of small barite pebbles and 
some hematite occur in the concentrates. 
On claim No. 17- A a hydraulic plant was installed during the season of 1904. 
About a mile of combined ditch and flume had been put in, about 3,000 feet of which 
was flume, 32 by 18 inches, delivering 300 inches of water under a head of about 75 
feet. A No. 1 Hendy Giant with a 3-inch nozzle was being used (PL V, B). 
In working the ground the niggerheads and moss are torn up with a team and 
harrow and washed off with the nozzle. The ground is then left for a week, during 
which time the muck will thaw 1 to 2 feet. This is then washed off. The process 
is repeated until the top is removed. The remaining gravel thaws much more rap- 
idly than the muck. It is found that the gravel can thus be thawed and made ready 
for sluicing much faster than a hydraulic giant working steadily can wash the gravel 
into the sluice boxes. In one instance an area 125 by 250 feet was worked out in 
40 days. The gravels are 2 to 12 feet thick, averaging about 6 feet, and are covered 
by 1 to 40 feet of muck. The maximum thickness was found at the mouth of a small 
tributary gulch where the gravel is mixed with angular fragments of rock. The 
muck contains much ground ice, which -thaws readily when hydraulicked. The ice 
occurs occasionally as " dikes." One such was encountered over 400 feet long and 2 
feet thick, intersecting the surface layer of muck and a flat lenticular mass of ground 
ice down to the gravel, making a depth of 12 to 15 feet. 
The gold is found through the lower 3 feet of gravel and in the rough broken bed 
rock, which is made up of diabase and thin-bedded quartzite. It is bright and 
smooth, and nuggets up to 10 ounces in weight have been found. There is a> small 
amount of rougher gold. , Colors of gold are said to occur throughout the length of 
the creek, but no workable deposits have been found above the eastern limit of old 
gravels on the high bench already described. The larger part of the gold has prob- 
ably been reconcentrated from this bench. The smaller portion of rough gold has 
probably a local source in the rocks of the creek valley. Drifting is done in the 
winter at a number of places on the creek, but little information could be obtained as 
to results. 
LITTLE MINOOK CREEK. 
(ieaeral description. — Little Minook Creek empties into Minook Creek about 5 miles 
from the Yukon and about 1 J miles above the mouth of Hunter Creek, and has so far 
been the largest producer of the region. In drier years it carries scarcely a sluice head 
of water. It has a grade of 100 feet or less per mile in the lower 3-mile section to which 
all the mining has been confined, and its course is remarkable in being nearly par- 
allel to Hunter Creek, though considerably shorter, as it has a length of only about 8 
miles. Like Hunter Creek it makes a sharp bend upon entering the high bench about 
3 miles from Minook Creek. Above this bend Little Minook Creek has a maturer 
character, as shown by the more crooked valley and greater number of tributaries, 
while in its course through the bench it has a straight sharply V-shaped valley 
Bull. 280—06 3 
