W wright ND ] DEVELOPMENTS IN SOUTHEASTERN ALASKA. 53 
of these mines for the year ending December 31 will not be published 
in time to include the data in this paper. The mining methods 
employed have been very clearly described by Mr. K. A. Kinzie," 
superintendent of the Treadwell mines, and the geology of the ore 
deposits has been given in much detail by A. C. Spencer, 6 of the V. S. 
Geological Survey. 
Within the Gold Creek drainage area work has been continued, with 
promising results, at the Ebner, the Humboldt, the Alaska- Juneau, and 
the Perseverance mines; but, though large-scale operations on these 
properties have been proposed, no great advancement has been made in 
this direction. 
At Little basin, the Jualpa Mining Company's placer property, 
within a mile of Juneau, operations have been confined to the installa- 
tion of a flume sufficient to control the waters of Gold Creek during 
their highest stages and thus permit hydraulic operations to be car- 
ried on with safety. This flume, which follows the south side of the 
valley slope, is 4,250 feet in length, 20 by 9 feet in cross section, and 
has a grade of 1.66 per cent. At the head of the basin a dam has been 
built in bed rock, and gates have been constructed to control the flow 
of water into the flume or creek bed. A tunnel 2,000 feet long is 
being extended 400 feet to a point under the basin where it will tap 
the gravel bed 90 feet below the surface. Early in the spring, when 
this tunnel is completed, hydraulicking of these auriferous gravels 
will be commenced. 
The Sheep Creek mines, 5 miles east of Juneau, are again being sys- 
tematically developed and have been good producers in both gold and 
silver this past year. 
MINES SOUTH OF JUNEAU. 
The Snettisham mine, approximately 35 miles south of Juneau, has 
continualh 7 produced good ore from its relatively small deposit, and 
the 20-stamp mill on the property has been in operation during the 
greater part of the year. 
At Sumdum, 50 miles southeast of Juneau, operations have ceased 
and the mining plant is to be removed, owing to the failure of the 
quartz ledge in depth, prohibiting profitable extraction. It is doubt- 
ful whether mining will ever be resumed at this place. 
Still farther south, at Windham Bay, developments have continued 
on many of the properties, though none of these have as yet proved 
productive. The mineral belts are low in gold values and though 
occasional seams with visible gold are found the ores will require very 
economical methods of extraction to insure profitable mining. 
a Kinzie, R. A., The Treadwell group of mines, Alaska: Trans. Am. Inst. Min. Eng., vol. 34, pp. 
334-386. 
b Spencer, A. C., The geology of the Treadwell ore deposits, Alaska: Trans. Am. Inst. Min. Eng., 
vol. 35. 
