28 ALASKAN MINERAL RESOURCES IN 1904. [bull. 259. 
to 60 or more feet. The values were carried in 18 inches to over 7 feet of gravel, 
with a width varying from 45 to 250 feet. The coarsest nugget was valued at $190. 
The average values were probably 5 to 10 cents to the pan, but were occasionally 
much higher. Drifting with steam point was the favorite method of mining in 1904. 
Conditions are practically the same on Pedro, Cleary, and Fairbanks creeks, and 
they all carry about the same amount of water, which in dry seasons will probably 
be short of the demand. All are dependent on the lower valleys of the larger 
streams for lumber. 
The quantity of gold in the gravels, and their extent, seem sufficient to give the 
camp a permanence like that of the other placer camps in the Yukon-Tanana 
country. The depth of the deposits has rendered the work of development a slow 
one. The claims require capital for their development, and the method used most 
extensively is steam drifting with points. The expense of working the ground con- 
sumes probably from one-third to one-half of the output, and the total production 
from the close of navigation in 1903 to the end of July, in 1904, was probably not 
less than $350,000. 
No large quartz veins were observed, and the conditions are apparently unfavor- 
able for quartz mining. The origin of the placer gold is probably to be found in the 
small quartz stringers which occur generally in the schists. 
BONNERVILLE DISTRICT. 
The large influx of prospectors to Fairbanks led to an examination 
of the adjacent regions and resulted in the finding of gold along the 
base of the Alaskan Range 50 miles south of Fairbanks. So far as 
known the commercial possibilities of this new held have not yet been 
demonstrated, though a number of miners appear to be satisfied at the 
outlook. This area south of the Tanana was formed into a new dis- 
trict under the name of " Bonnerville." 
The Alaskan Mountains which bound the Tanana on the south are 
known to be in part made of metamorphic rocks which are quite likely 
to be mineralized. The range falls off rather abruptly to the Tanana 
Valley floor, and its northern front is partly buried under a mantle of 
stratified gravel deposits. These beds were observed by the writer 
along the Cantwell River Valley, where they are several hundred feet 
thick, and are probably auriferous. The writer's investigations did 
not establish the presence of workable placers, but an abundance of 
fine colors of gold was found in the beds of streams which dissect the 
gravel deposits. A natural inference is that the heavy gravel beds 
themselves are auriferous, though opportunity was lacking to make 
any tests. 
These heavy bench gravels lie in such a position that, should they 
prove to carry values, they could be hydraulicked to advantage. 
Moreover, their location along the flank of the mountains gives oppor- 
tunities for bringing water to them under any head desired. If gold 
has, therefore, been found in this district in commercial quantities, 
the conditions for exploration seem more favorable than in most of the 
Yukon camps. It should be borne in mind, however, that the district 
lies 50 or more miles from water transportation. 
