pr rim; ton.] METHODS OF MINING, AND CONDITIONS. 31 
ical plants. Solidly frozen creek deposits exceeding 15 feet in depth 
can be most economically worked by drifting methods, as heretofore. 
Experience gained in the Klondike has been invaluable to the miners 
now developing the new Fairbanks field. There is room, however, 
for considerable improvement and redaction of expense in the methods 
employed. 
The natural conditions prevailing in the Alaska interior gold field 
imply great age and erosion subsequent to any deposition beneath sea 
level. Topographic conditions exercise a remarkable control over the 
methods which can profitably be employed in gravel mining, and the 
prospective miner neglects a vital part of his preparation if he does 
not study the topographic features of a given district in detail before 
entering upon his operations. In California and Australia the geologic 
and topographic conditions favor the placer miner. In other coun- 
tries, notably Siberia, Alaska, and the Yukon Territory, they are inimi- 
cal to his success. In Alaska, as a rule, alluvial gold is almost entirely 
lacking where timber and water are plentiful, grades are steep, and the 
ground is unfrozen. Where gold is distributed in paying quantity, 
water supply is inadequate, timber is poor or altogether lacking, the 
miner must provide grade for his boxes and dump for his tailings b}^ 
artificial means, and must meet the formidable obstacle of solidly fro- 
zen alluvium. Bench deposits, where gravel can be moved on natural 
grade, occur in both the Forty mile and Rampart districts of interior 
Alaska, and have been made to produce a small amount of gold by the 
hydraulic method. Although it is not impossible that extensive and 
valuable bench deposits may yet be found, no deposit comparing either 
in extent or in richness with the famous " White Channel "of the 
Klondike has been discovered. 
In that portion of the Alaska interior lying between Circle, on the 
ukon, and Fairbanks, on the Tanana, the mountains rise to heights of 
rom 1,500 to 2,000 feet above the level of the streams, have rounded 
ops, and slope to the intervening valleys at angles which do not exceed 
degrees, and often are not greater than 10 degrees. The streams 
nd valleys are on a gently descending plain, the grade of which does 
ot exceed 3 per cent, except in the upper one-half mile, and frequently 
not over 1 per cent. The mountains are referred to by the inhabi- 
ants as " domes," and the word fairly well describes them. They 
•resent what corresponds most nearly to the upper segment of a great 
lipsoid except in places where the erosion has not been sufficient 
accomplish the obliteration of a still more ancient topography. 
jihis ancient surface, remnants of which are visible on the tops of the 
ighest mountains, was evidently a base-leveled plain, which was 
bproximately 2,500 feet above the present drainage plain. Although 
ae base-leveling is apparent to the eye, it is not evinced by the 
resence of rounded gravel on its surface. The lack of gravel is 
