78 FORTYMILE, BIRCH CREEK, AND FAERBANKS PLACERS, [bull. 251 
range from 2 to 25 cents to the pan and occasionally run much 
higher. 
Black sand, iron pyrites, garnet, rutile, and a mineral which 
proved, on being tested by Mr. Hess, to be cassiterite, the oxide of tin, 
are found associated with the gold. 
The depth to bed rock on Chatham Creek varies from 10 to nearly 
30 feet. There is but a thin covering of muck on the gravels, which 
consist mostly of angular fragments of quartzite-schist with a small 
proportion of fine-grained granite, which outcrops near the head of 
the creek. The pay gravels average about 3 feet in thickness, and 
the values do not range as high as on Cleary Creek. Some good 
ground has been worked, however, and the creek, in proportion to its 
size, has been a good producer during the past season. The gold is 
rougher than that on Cleary Creek and is apparently close to its 
source in the bed rock. 
The conditions on Wolf Creek are similar. The depth to bed rock 
near the head of the creek is about 10 feet. There is little muck and 
the gravels are composed of angular fragments of quartzite-schist, 
with some vein quartz. The gold is very rough and gritty, and the 
occurrence here is interesting in bearing on the origin of the gold 
from the quartzite-schist, which is the only kind of rock observed 
about the head of the creek. 
In 1903 several claims were being worked on Cleary Creek, notably 
Discovery claim, and on Chatham and Wolf creeks. Only drifting; 
methods had been used on Cleary Creek, on account of the great 
depth to bed rock. Open-cut work had been done on portions of 
Chatham and Wolf creeks. 
Discovery claim, on Cleary Creek, is located near the bend, about 
opposite the mouth of Wolf Creek. A good season's work was done 
here in 1903. The depth to bed rock is about 18 feet. A 6-horse 
power boiler was used to operate 5 steam points, which in ten hours 
thawed about 16 cubic yards of dirt, which were hoisted by a hand 
windless to a dump box 18 feet long by 3 feet wide, and washed 
through the sluice boxes by a stream of water entering from the 
side of the box. A scrubbing brush w T as in frequent use to wash the 
sticky gold-containing clay from the larger rock fragments. A 
least one sluice head, equivalent to about 50 miner's inches, wa 
required to wash the dirt, and at times during the season of 1903 th 
supply had fallen short of this quantity. About 600 cubic yards o 
dirt had been washed from July to September, 1903. The outfit is 
shown in PI. XV, B. Prospect holes were being sunk on a few 
claims below Discovery claim. Thawing w r as accomplished by th 
use of hot rocks. About three 10-pan bucket fuls were thrown in 
the "holes which were being sunk, and on cooling w r ere shoveled on 
along with the thawed gravel. Two fires a day were used, and the 
