ECONOMIC GEOLOGY. 45 
claim No. 4 the depth to bed ruck near the east side of the valley was 
found to be nearly 100 feet, while on the claim above, a hole 1 on the 
west side of the valley encountered bed rock at 40 feet. The matter 
is further complicated by a terrace (20 to 40 feet) of fine silt, with 
a little sand and gravel, remnants of which are preserved at various 
places along both slopes of the valley. The bed rock underneath this 
terrace appears to lie at about the same altitude as that under the 
creek bed, but holes sunk through the terrace to bed rock are neces- 
sarily much deeper than those in the valley floor. A still higher ter- 
race has been found along the east side of the valley near a tributary 
called Ready Bullion Creek. Here a heavy deposit of silt 40 to 60 
feet deep was found resting on some well-washed gravels which over- 
lie a bed-rock floor standing 100 to 200 feet above that of the creek 
bed. These high gravels are known to carry colors and are worthy 
of further investigation. The gravels are iron stained, like those 
of the bench placers on Cripple Creek. 
The gravels of Esther Creek are in the main well rounded and are 
made up principally of mica and quartz-mica schist. Some large 
bowdders of quartz, the larger of which reach 2 feet in diameter, are 
also present. Granite pebbles are not uncommon, and in some places. 
notably on No. 4 below, they form a large percentage of the gravels. 
The bed rock, as stated, is generally a schist, though in some places 
granite has been found. The schist ranges from a fine-grained mica 
variety, which' is as a rule deeply weathered, to a harder quartzose 
phase which approaches a quartzite and is commonly blocky. The 
ground is usually frozen, but one belt of thawed ground has been 
found. The pay streak as mined averages between 5 and 6 feet, of 
which from half to two-thirds is gravel and the balance weathered 
bed rock. The width of the pay streak, as defined by the present 
cost of mining, is about 40 to 50 feet for the upper part of the creek. 
The values in the material hoisted probably average $4 to $6 to the 
cubic yard. 
Esther Creek was first staked in 100.°), and some careful prospecting 
was done on it during the following year, but its output did not 
become important until L906. It now has an established position 
as a large gold producer, and there is much ground on the creek 
which has not been prospected. 
In 11)07 several mines were in operation on the east side of Cripple 
Creek and are reported to be working on bench gravels, but these 
deposits have not been studied. These gravels are red like the bench 
gravels on Esther Creek. Some gold has been taken out. but little 
mining except this has been done on Cripple Creek. 
Alder Creek has yielded no gold, though the gravels are -aid to be 
auriferous, and it appears probable that this creek also lies in the 
