48 FAIRBANKS AND RAMPART QUADRANGLES. 
posits, and the available water supply. Only a small part of the 
ground has a grade of over 100 feet to the mile and most of it has 
considerably less. The deposits worked range from a few feet to over 
120 feet in thickness. The creeks are small, carrying ordinarily 
200 to 400 miner's inches of water. In dry seasons the present sources 
of water supply would be inadequate, and, while thus far only short 
ditches have been in use, a project is under way to supply some of the 
areas with water from the upper part of Chatanika Valley by means 
of a ditch about 75 miles long. 
PROSPECTING. 
As the pay streak, if present, lies almost everywhere on bed rock, 
the chief work of prospecting consists of sinking holes to bed rock. 
It is usually necessary to thaw the ground, and while crude methods 
requiring wood fires or hot water are still in use, the most approved 
method, and the one most commonly employed, is that carried on 
by means of steam. Small, portable, knockdown steam-thawing 
outfits that can be packed on horses are now obtainable, thus permit- 
ting prospecting in remote areas. After the ice has been melted the 
material to be excavated is loosened with a pick, shoveled into a 
bucket, and hoisted to the surface, usually by hand windlasses. If 
the ground is deep the prospect shaft is generally timbered to the 
depth of the overlying muck. The most formidable difficulty encoun- 
tered in sinking is live water, which often necessitates the abandon- 
ment of shafts. Great depth of ground also increases the difficulty 
of sinking holes, and consequently makes the work of locating the 
pay streak slow. 
OPEN-CUT MINING. 
The ground is generally stripped first of all by sluicing off the 
overlying muck. A bed-rock drain is then constructed, and an open 
cut of sufficient width for one or two sets of boxes is carried gradu- 
ally up the valley. In some cases the gravel is hoisted by steam 
power entirely out of the cut to boxes set above the surface and to 
one side of the workings. By this method a frequent resetting of 
the boxes is avoided and there is a better disposal of tailings. Gravel 
is hoisted by derrick, by automatic trolley, or by a rock pump. 
Where the last method is used a set of boxes is placed on the bottom 
of the cut, the coarsest pieces are forked out, and all the rest of the 
material is elevated through the pump to the boxes on the surface. 
Owing to the depth of the gravels the open-cut method and its modi- 
fications are of limited application. 
DRIFTING. 
The methods of working the deep gravels of this region are simi- 
lar to those employed in the deep gravels of other fields, with the 
modifications rendered necessary by the frozen character of the 
