LODE MINING IN SOUTHEASTERN ALASKA. 53 
and 660-foot levels, and to some extent from the 770-foot and 880- 
foot levels. The last annual report gave a total of 233,985 tons ore 
milled to January 1, 1906, yielding $703,765, or an average of $3.01 
per ton. 
At the Ready Bullion mine the inclined shaft has been sunk to the 
1,500-foot level and developments furthered on the 1,350-foot and 
l;200-foot levels. The ore mined was principally from the 750-foot 
and 1,025-foot levels. The yearly report to January 1, 1906, gave a 
total tonnage of 233,480 tons, yielding $439,815. 
The power plants that operate this group of mines have undergone 
many interesting changes within the last year. The supply of water 
power has been increased by the building of a new dam at the head- 
waters of Fish Creek, thus forming a storage basin which will increase 
the supply by 200 miner's inches during the two months of low water 
in the winter. This will increase the amount of all ore milled by water 
power from 87 per cent to 93 per cent. Another large saving is to be 
made by the use of oil in place of coal, thus doing away with a large 
expense in the handling of coal and a reduction in the initial cost. 
For this purpose large supply tanks are being installed, pipe lines laid, 
and oil burners introduced in the boilers. 
The Nevada Creek mine, belonging to the Alaska Treasure Consoli- 
dated Mines Company, on the southeast end of Douglas Island, has 
been energetically developed this year, both underground and with 
reference to surface improvements. The mine is located 1 mile from 
tide water, at an elevation of 825 feet. At this point a tunnel 700 
feet in length has been driven in a southwesterly direction, nearly at 
right angles to the trend of the rock structure. Drifts 100 to 300 feet 
in length have been extended to the northwest and southeast from 
points 450 and 550 feet from the mouth of the tunnel, and from these 
other exploratory crosscuts have been driven. The country rock is 
essentially greenstone and greenstone schist, with intercalated bands 
of graphitic slate. The ore bodies may be defined as narrow bauds 
parallel with the rock structure within which a concentration of metal- 
lic minerals has taken place. The ore minerals, essentially auriferous 
pyrite with sulphides of copper, lead, and zinc, are accompanied by 
both quartz and calcite veinlets. Intruding these rock beds are 
narrow dikes of basalt, striking in a northwesterly direction, which 
appear to have little effect on the ore occurrence. A change in the 
structural trend or a wrinkling of the schistose beds is indicative of 
an ore body. ' At such a place, 450 feet from the mouth of the tunnel, 
an ore body 10 feet wide and containing a narrow seam of high-grade 
quartz ore 2 to 12 inches wide is being opened. The values in this 
body appear to be limited to a distance of 100 feet along its strike, and 
the rock structure indicates that the deposit is in the form of a shoot 
pitching at an angle of 40° in a northwesterly direction and parallel 
