8 ALASKAN MINERAL RESOURCES IN 1905. 
Mining continues in theKobuk River region, in the northern part of Alaska, 4 claims having 
been worked in 1905 according to Mr. M. F. Moran. The shortness of the season and the high 
cost of provisions have made it impossible to work anything but the very richest claims. 
It is said that unless a claim pays more than $10 a day to the man, it can not be developed 
A little placer gold, estimated at $5,000 in 1905, has been produced in this field, but most of 
the miners have left the region. 
COPPER. 
In 1905 there were two copper-producing districts, Ketchikan and Prince William Sound 
and in three more, the Chitina (Copper River basin), White-Tanana, and Kenai districts 
consider;! ble prospecting was done. Copper has also been found in other parts of south 
eastern Alaska and reported from a field lying immediately west of Cook Inlet. The coppe; 
deposits of Prince of Wales Island and of Prince William Sound are described on pages 46-5J 
and 78-87. Their rapid development, as compared with that of the inland districts, is dm 
to their proximity to tide water, open to navigation throughout the year. Two smelter: 
have been completed on Prince of Wales Island, but the bulk of the Alaska ores are sfil 
shipped to Tacoma. 
In the Chitina district prospecting is steadily progressing on the copper properties lyinj 
on the southern slope of the Wrangell Mountains. At present this field is reached only afte 
a 200-mile journey over a rough trail. Freight charges to the district are as high as a dolla 
a pound in summer and 15 to 'JO cents a pound in winter. In spite of this excessive cost 
considerable development work has been done in the district. The general features of th 
geology have been described in previous reports by the Geological Surveys in which it ha 
been shown that the copper .deposits occur at or near the contact of an extensive series c 
ancient lavas and a white crystalline limestone. The latter is probably of Permian ag< 
The ores found in place are chiefly sulphide, for the native copper, occurring in the gravel 
near the east end of the held, has not been traced to its bed-rock source. The results of th 
prospecting of the last two years indicate a greater persistency at depth than was expeete 
from the surface croppings. At the east end of the field a vein has been followed to a dept 
of about a hundred feet, and a lode near the west end of the field has been tested by die 
mond drilling to a depth of about 51) feet. The reported results of this prospecting indicat 
a permanence of the ore bodies which augurs well for the development of an important coi 
per district. Further operations must await the construction of a railway from the coas 
A second, less-known copper belt lies north of the Wrangell Mountains, stretching wesi 
ward from the international boundary, at the head of White River, to the headwater basir 
of Tanana River. These ore bodies are closely associated with greenstones and limestone 
but their form of occurrence is less well known than in the case of the southern field. Tl 
reports of the prospecting of the past year warrant a further investigation of this belt. Tl 
permanent development of this field can be accomplished only with the aid of railway facil 
ties, but the fact that water transportation is available within 50 miles of any point in tl 
district is of the greatest possible importance, and this was demonstrated last year by M 
Henry Bratanober, who took a small steamer up the Tanana to the mouth of the Nabesn; 
Mention should be made of the occurrence of lodes carrying copper sulphide in the Ken. 
Peninsula. Little is known of the character of these deposits, but they appear to lie in 
southwesterly extension of the belt of metamorphic rocks which carry copper in the Prim 
William Sound region. Work on these deposits has been stimulated by the construction < 
the Alaska Central Railway. 
a.Schrader, F. C, and Spencer, Arthur C, The Geolopv and Mineral Resources <>f a Part of the Copp 
River District; special pub. U. S. Geo]. Survey, L901. Mendonhall, W. C, and Schrader, F. ('.. Tl 
mineral resources of the Mount Wrangell district, Alaska: Prof. Paper U. S. Geol. Survey No. 1"), L903 
