22 THE PORCUPINE PLACER DISTRICT, ALASKA. [bull. 236. 
holders bonded or leased their properties, while others formed com- 
panies in order to operate on a large scale. The conditions to be met 
require a still further combination of interests for economic exploita- 
tion, and negotiations are now being made to bring the entire creek 
under a single management. 
The extensive gravel bed of Klehini River is known to contain 
some gold, though no comprehensive tests have been made to show its 
probable value. Dredging would seem to be the only practical >le 
method of mining this deep deposit. 
In describing the placer properties those at the mouth have been 
first considered, while the claims following are referred to in regular 
order (PL VII). 
DESCRIPTION OF CLAIMS. 
PORCUPINE CREEIK. 
Delta claims. — On the western bank of the Porcupine, near its mouth, 
the gravel bench formed by the old delta was formerly all staked, 
though at present only the claims neighboring the creek are held, 
and on these no more than the required assessment work has been 
done. The depth of the deposit is unknown and the few test pits on 
the several claims are said to have given only low values. 
Cranston claim. — This claim, the first on the creek under develop- 
ment, is 1 mile from the mouth of the Porcupine. The gravel bed is 
40 feet in depth, the top of the deposit forming a bench on the east 
side 20 feet above the stream. The gravels are said to carry good 
values, but the gold is not uniformly distributed. Next to bed rock 
is a layer 2 to 3 feet deep carrying high values in gold, though this is 
sometimes cut off by ridges in the bottom of the channel. Overlying 
this is a 15-foot bed less rich in values, containing many quartz peb- 
bles and some bluish clay. The next 2 feet are of clay and small 
gravel wash, probably of glacial origin. Though this material was 
supposed to be quite barren a sample submitted to fire assay gave a 
value of over $20 per ton, showing this .stratum to be worthy of closer 
examination. Above the clay there is 15 to 20 feet of yellow gravel, 
averaging 150 feet in width and carrying good values (fig. 2). 
Besides gold, platinum is said to occur in the black sands, but a labo- 
ratory test did not verify the report. Galena, magnetite, chalcopy- 
rite, some arsenop3 7 rite, and a large amount of p} 7 rite occur in the 
concentrates. 
To develop this property a flume 1,200 feet in length was built 
along the creek bank, supphdng the hydraulic hose used to work the 
gravels and furnishing power for the bucket elevator, centrifugal 
pump, and sawmill. A 6-horsepower derrick, receiving power from 
a steam engine, has been installed to hoist bowlders too large for the 
